This document contains 20 Java programs that solve various math and logic problems. Each program contains comments describing the problem, declares variables and constants, gets user input, performs calculations, and outputs results. The programs include examples of summing numbers, finding quotients/remainders, calculating area of a circle, compound interest, time conversions, and if/else conditional logic.

1. Problema1
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package problema.nº1;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class ProblemaNº1 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
int n1,n2,s;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("numero 1:");
n1 = Integer.parseInt(in.readLine());
System.out.println("numero 2:");
n2 = Integer.parseInt(in.readLine());
s=n1+n2;
System.out.println("");
System.out.println("suma: " +s);
}
}
Problema 2
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package problema2;
import java.io.*;
/**
*
* @author RositaRoblesArmas

2. */
public class Problema2 {
/**
* @param args the command line arguments
*/
public static void main(String[] args)throws IOException {
//varible
int n1,n2,c,r;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("numero 1:");
n1 = Integer.parseInt(in.readLine());
System.out.println("numero 2:");
n2 = Integer.parseInt(in.readLine());
//proceso
c=n1/n2;
r=n1%n2;
//salida
System.out.println("");
System.out.println("cociente: " +c);
System.out.println("residuo: " +r);
// TODO code application logic here
}
}
Problema3
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package problema.pkg3;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class Problema3 {
/**
* @param args the command line arguments
*/
public static void main(String[] args)throws IOException {
//variable
float vv,igv,pv;
//entrada

3. BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("valor de venta:");
vv =Float.parseFloat(in.readLine());
//proceso
igv = vv *0.18f;
pv = vv+ igv;
//salida
System.out.println("");
System.out.println("igv: " +igv);
System.out.println("precio de venta: " +pv);
// TODO code application logic here
}
}
Problema4
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package problema004;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class Problema004 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
short a,n;
int p;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("a: ");
a=Short.parseShort(in.readLine());
System.out.println("n: ");
n=Short.parseShort(in.readLine());
// TODO code application logic here
p=(int)Math.pow((double)a, (double)n);

4. System.out.println("");
System.out.println("Potencia: "+p);
}
}
Problema5
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package problema5;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class PROBLEMA5 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
short n,r;
int a;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("a: ");
a=Integer.parseInt(in.readLine());
System.out.println("n: ");
n=Short.parseShort(in.readLine());
// TODO code application logic here
r=(short)Math.pow((double)a, (1/(double)n));
System.out.println("");
System.out.println("Radicación: "+r);
// TODO code application logic here
}
}
Problema6
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package problema6;
import java.io.*;
/**
*
* @author RositaRoblesArmas

5. */
public class PROBLEMA6 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
// TODO code application logic here
int n, ni, r;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Número: ");
n=Integer.parseInt(in.readLine());
r=n%10;
n=n/10;
ni=r*10;
r=n%10;
n=n/10;
ni=(ni+r)*10;
r=n%10;
n=n/10;
ni=(ni+r)*10;
r=n%10;
n=n/10;
ni=(ni+r)*10;
ni=ni+n;
System.out.println("");
System.out.println("Inverso: " + ni);
}
}
Problema7
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package problema07;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class PROBLEMA07 {

6. /**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
// TODO code application logic here
int n,s;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Número: ");
n=Integer.parseInt(in.readLine());
s=(n*(n+1))/2;
System.out.println("");
System.out.println("Suma: " + s);
}
}
Problema8
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package problema8;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class Problema8 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
float c, r, t, i, m;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Capital: ");
c=Float.parseFloat(in.readLine());
System.out.println("Tasa de interes: ");
r=Float.parseFloat(in.readLine());
System.out.println("Tiempo: ");
t=Float.parseFloat(in.readLine());
m=(float)(Math.pow((double)(1+r/100),(double)t))*c;
i=m-c;

7. System.out.println("");
System.out.println("Interes: " + i);
System.out.println("Monto: " + m);
}
}
Problema9
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package problema9;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class Problema9 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
// TODO code application logic here
//const float PI = 3.14159F;
final float PI=3.14159f;
float a,r;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Radio: ");
r=Float.parseFloat(in.readLine());
a=(float)(PI*(Math.pow((double)r, 2.0)));
System.out.println("");
System.out.println("Õrea: "+a);
}
}
Problema10
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8. package problema10;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class Problema10 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
final int HORA=3600;
final int MINUTO=60;
int t,h,m,s;
BufferedReader in =new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Tiempo en segundos: ");
t=Integer.parseInt(in.readLine());
h=t/HORA;
//t=t%HORA;
m=t/MINUTO;
s=t;
System.out.println("");
System.out.println("Horas: "+h);
System.out.println("Minutos: "+m);
System.out.println("Segundos: "+s);
// TODO code application logic here
}
}
Problema11
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package problema11;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class Problema11 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
int n1, n2, m = 0;

9. BufferedReader in=new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Número 1: ");
n1=(int) Integer.parseInt(in.readLine());
System.out.println("Número 2: ");
n2=(int) Integer.parseInt(in.readLine());
if(n1>n2)
m= n1;
if(n2>n1)
m= n2;
System.out.println("");
System.out.println("Mayor:"+m);
Problema12
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package problema12;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class Problema12 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException{
int n;
String r = "";
BufferedReader in=new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Número: ");
n=(int)Integer.parseInt(in.readLine());
if (n>0)
{
r="POSITIVO";
}
if (n<0)
{
r="NEGATIVO";
}
if(n==0)
{
r="NEUTRO";
}
System.out.println("");
System.out.println("Resultado: "+r);

10. }
}
Problema13
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package problema13;
import java.util.Scanner;
/**
*
* @author RositaRoblesArmas
*/
public class Problema13 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
char c;
//String r="";
System.out.println("Caracter");
Scanner teclado=new Scanner(System.in);
c=teclado.next().charAt(0);
if(c=='a'||c=='e'||c=='i'||c=='o'||c=='u'||c=='A'||c=='E'||c=='I'||c==
'O'||c=='U'){
//r="es vocal";}
System.out.println("ES VOCAL");
} else{
//r="no es vocal"; }
System.out.println("NO ES VOCAL");
}//System.out.println("la letra ingresada "+r);
}
}
Problema14
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package problema014;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/

11. public class Problema014 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
int n;
String r;
BufferedReader in=new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Numero: ");
n=Integer.parseInt(in.readLine());
if(n%3==0 && n%5==0)
{
r="SÍ ES MÚLTIPLO DE 3 Y 5";
}
else
{
r="NO ES MÚLTIPLO DE 3 Y 5";
}
System.out.println("");
System.out.println("Resultado:" + r);
System.out.println();
}
}
Problema15
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package problema015;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class PROBLEMA015 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException{
// TODO code application logic here
int n;
String r;
BufferedReader in=new BufferedReader(new
InputStreamReader(System.in));

12. System.out.println("Número: ");
n=Integer.parseInt(in.readLine());
if(n%2==0)
{
r= "PAR";
}
else
{
r= "IMPAR";
}
System.out.println("");
System.out.println("Resultado: " + r);
System.out.println();
}
}
Problema16
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package problema16;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class PROBLEMA16 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException{
int n1,n2,n3,m;
BufferedReader in=new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Número 1: ");
n1= Integer.parseInt(in.readLine());
System.out.println("Número 2: ");
n2=Integer.parseInt(in.readLine());
System.out.println("Número 3: ");
n3= Integer.parseInt(in.readLine());
if (n1>n2)
{
if(n1>n3)
{
m=n1;
}
else

13. {
m=n3;
}
}
else
{
if(n2>n3)
{
m=n2;
}
else
{
m=n3;
}
}
System.out.println("");
System.out.println("Mayor: " +m);
}
}
Problema17
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package problema017;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class PROBLEMA017 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException{
int n,r;
BufferedReader in=new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Número: ");
n = Integer.parseInt(in.readLine());
if (!(n%2==0))
{
r=n*2;
}
else
{
r=n*3;
}

14. System.out.println("");
System.out.println("Resultado: " + r);
System.out.println();
}
}
Problema18
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package problema18;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class PROBLEMA18 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException{
int n1, n2, n3, mayor, inter, menor;
BufferedReader in=new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Número 1: ");
n1= Integer.parseInt(in.readLine());
System.out.println("Número 2: ");
n2=Integer.parseInt(in.readLine());
System.out.println("Número 3: ");
n3= Integer.parseInt(in.readLine());
if(n1 > n2 && n1 > n3)
{
mayor=n1;
}
else
{
if (n2 > n1 && n2> n3)
{
mayor=n2;
}
else
{
mayor=n3;
}
}
if(n1 < n2 && n1 < n3)
{
menor=n1;
}

15. else
{
if (n2 < n1 && n2 < n3)
{
menor=n2;
}
else
{
menor=n3;
}
}
inter=(n1 + n2 + n3)- (mayor + menor);
System.out.println("");
System.out.println("Mayor:" + mayor);
System.out.println("Inter:" + inter);
System.out.println("Menor:" + menor);
System.out.println();
}
}
Problema19
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package problema19;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class Problema19 {
/**
* @param args the command line arguments
*/
public static void main(String[] args)throws IOException{
final float D1=0.1F;
final float D2=0.2F;
final float IGV=0.18F;
float c,m_d, m_igv, p;
BufferedReader in=new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Consumo: ");
c=(float)Integer.parseInt(in.readLine());
if(c<=100)
{
m_d=c * D1;
}
else
{

16. m_d=c * D2;
}
m_igv=(c-m_d) * IGV;
p= c - m_d + m_igv;
System.out.println("");
System.out.println("Monto descuento: " + m_d);
System.out.println("Impuesto IGV: " + m_igv);
System.out.println("Importe a pagar: " + p);
System.out.println();
}
}
Problema20
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package problema20;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class Problema20 {
/**
* @param args the command line arguments
*/
public static void main(String[] args)throws IOException{
final float D1 = 0.1F;
final float D2 = 0.2F;
final float D3 = 0.3F;
final float IGV = 0.18F;
float c, m_d, m_igv, p;
BufferedReader in=new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Consumo: ");
c=(float)Integer.parseInt(in.readLine());
if(c>200)
{
m_d=c*D3;
}
else
{
if(c>100)
{
m_d=c*D2;

17. }
else
{
m_d=c*D1;
}
}
m_igv=(c-m_d) * IGV;
p=c-m_d+m_igv;
System.out.println("");
System.out.println("Monto descuento: " + m_d);
System.out.println("Impuesto IGV: " + m_igv);
System.out.println("Importe a pagar: " + p);
System.out.println();
}
}
Problema21
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*/
package problema21;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class Problema21 {
/**
* @param args the command line arguments
*/
public static void main(String[] args)throws IOException{
int t;
String c;
BufferedReader in=new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Temperatura: ");
t = Integer.parseInt(in.readLine());
if (t<10)
{
c="FRIO";
}
else
{
if (t>9 && t<21)
{
c="NUBLADO";
}
else

18. {
if (t>=21 && t<=30)
{
c="CALOR";
}
else
{
c="TROPICAL";
}
}
}
System.out.println("");
System.out.println("Clima: " + c);
System.out.println();
}
}
Problema22
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package problema22;
import java.util.Scanner;
/**
*
* @author RositaRoblesArmas
*/
public class Problema22 {
/**
* @param args the command line arguments
*/
public static void main(String[] args){
Scanner in =new Scanner(System.in);
final float DESC_G = 0.15F;
final float DESC_A = 0.2F;
final float REC_G = 0.1F;
final float REC_A = 0.05F;
//variables
float mc, m, tp;
//char tc,fp;
String r ;
String tc;
String fp;
System.out.println("Monto de compra: ");
mc=in.nextFloat();
System.out.println("Tipo de cliente: ");

19. tc =in.next();
System.out.println("Forma de pago: ");
fp=in.next();
if(tc=="G")
{
if(fp=="C")
{
m = mc * DESC_G;
tp = mc - m;
r = "DESCUENTO 15%";
}
else
{
m = mc * REC_G;
tp = mc + m;
r = "RECARGO 10%";
}
}
else
{
if (fp=="C")
{
m = mc * DESC_A;
tp = mc - m;
r = "DESCUENTO 20%";
}
else
{
m= mc * REC_A;
tp = mc + m;
r = "RECARGO 5%";
}
}
System.out.println("");
System.out.println(r + ": "+m);
System.out.println("Total a pagar: " + tp);
System.out.println();
}
}
Problema23
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package problema23;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class PROBLEMA23 {

20. /**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException{
float a,b,x;
BufferedReader in=new BufferedReader(new
InputStreamReader(System.in));
System.out.println("a: ");
a=Float.parseFloat(in.readLine());
System.out.println("b: ");
b=Float.parseFloat(in.readLine());
if(a!=0)
{
x=-b/a;
}
else
{
x=0;
}
System.out.println("");
System.out.println("x: " + x);
System.out.println();
}
}
Problema24
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package problema24;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class Problema24 {
/**
* @param args the command line arguments
*/
public static void main(String[] args)throws IOException {
double a,b,c,d,x1,x2;
BufferedReader in=new BufferedReader(new
InputStreamReader(System.in));
System.out.println("a: ");
a=(double) Integer.parseInt(in.readLine());
System.out.println("b: ");
b=(double)Integer.parseInt(in.readLine());
System.out.println("c: ");
c=(double) Integer.parseInt(in.readLine());

21. d = Math.pow(b,2)-4*c;
if(a!=0 && d>=0)
{
x1 = (-b+Math.pow(d,(1.0/2)))/2*a;
x2 = (-b-Math.pow(d,(1.0/2)))/2*a;
}
else
{
x1 = 0;
x2 = 0;
}
System.out.println("");
System.out.println("x1: " + x1);
System.out.println("x2: " + x2);
System.out.println();
}
}
Problema25
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package problema25;
import java.io.*;
/**
*
* @author RositaRoblesArmas
*/
public class Problema25 {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws IOException {
int h,m,s;
BufferedReader in=new BufferedReader(new
InputStreamReader(System.in));
System.out.println("Hora: ");
h= Integer.parseInt(in.readLine());
System.out.println("Minuto: ");
m=Integer.parseInt(in.readLine());
System.out.println("Segundo: ");
s= Integer.parseInt(in.readLine());
s+=1;
if (s==60)
{
s=0;
m+=1;
if(m==60)

22. {
m=0;
h+=1;
if(h==24)
{
h=0;
}
}
}
System.out.println("");
System.out.println("Hora: " + h);
System.out.println("Minuto: " + m);
System.out.println("Segundo: " + s);
System.out.println();
}
}