The document is a workbook for 9th standard students on solving problems using pairs of equations. It includes 4 activities with multiple questions in each activity. The questions cover topics like forming pairs of equations from word problems, solving simultaneous equations, ratios and proportions. For each question, the document provides the step-by-step workings and solutions. The objectives are to understand equations, identify pairs of equations in problems, and solve problems using pairs of equations.

1. WORKBOOK

2. STD 9

3. GENERAL OBJECTIVES
 To understand on equations
 To identify the pairs equations in the given
problem
 To solve problems by forming pairs of
equations

4. ACTIVITY 1
Try to answer the following questions through mental work
1. 5 books of the same prize and a pencil of Rs 5 were sold for fifty
five rupees. What is the prize of one book?
ans :
2. Mini’s father and mother give some apple to her such that
mother give double as father give. Suppose mini got 21 apples in
total. How much her father give to her?
ans :
3. Find the value of ‘x’ from the following equation
2x+y = 23 and
y = 5
ans :

5. ACTIVITY 2
Answer the following questions. You can do it in your brain or you
can use paper and pen for calculations.
1. In a box there white and black balls. The number of black balls is
eight more than the number of white balls ; the total number of balls
is four times the number of white balls. How many black and white
balls are there in the box?
ans :

6. 2. Four added to half of a number gives hundred. What is the
number?
ans :
3. Two persons divided hundred rupees between them and
one got ten rupees more than the other. How much did each
get?
ans :

7. 4. Raji’s age is three times that of her brother Rajan. After two
years , Raji’s age would be two times that of Rajan. How old
are they now?
ans :
5. A hundred rupee note was changed to ten rupee notes and
twenty rupee notes, eight notes in all. How many tens and
how many twenty notes are there?
ans :

8. ACTIVITY 3
Read the following questions carefully and solve them
1. The number of girls in a class is 4 more than the number of boys .
On a day when only 8 boys were absent, the number of girls were
double the number of boys. How many boys and girls are there in
that class?
ans :

9. 2. If 2 is added to the denominator of a fraction and the fraction is
simplified, we get 1/4. If instead, 1 is added to the numerator
and simplified, we get 2/5. what is the fraction?
ans :

10. 3. The price of a table and a chair together is 2500 rupees. The
price of 3 tables and 4 chairs of this kind is 8000 rupees. What is
the price of each?
ans :

11. 4. Thomas deposited 7000 rupees in all in two banks. The rate
of interest is 8% in one bank and 11% in the other. After a
year, he got 680 rupees as interest from both banks
together. How much did he deposit in each bank?
ans :

12. 5. Manu is 4 years younger than Mridula. 4 years back,
Mridula’s age was one and a half times Manu’s age. What
are their ages now?
ans :

13. ACTIVITY 4
Try to answer the following problems as your own
1. The price of 2 pens and 3 notebooks is 29 rupees; for 2 pens and 5
notebooks, it is 43. what is the price of each?
ans :

14. 2. The price of 3 pencils and 4 pens is 26 rupees. The price of 6
pencils and 3 pens is 27 rupees. What is the price of each?
ans :

15. 3. There are two cans, one large and one small. The small can
filled five times and the large can filled two times together give
20 litres. The small can filled two times and the large can filled
three times give only 19 litres. How much does each can
contain?
ans :

16. 4. Four times a number added to thrice another number gives 43.
twice the second number, subtracted from thrice the first gives
11. what are the numbers?
ans :

17. 5. Some autorikshaws and bikes are parked in a place. There
are 19 in all. The total number of wheels is 45. how many of
each vehicle are there?
ans :

18. 6. The sum of digits of a two-digit number is 11. if the digits of the
number are interchanged, we get a number which is 27 more
than the original number. What is the number?
ans :

19. ACTIVITY 1
1. 10
2. 7
3. 9
ACTIVITY 2
1. 4 white balls and 12 black balls
2. 192
3. 45, 55
4. Raji’s age = 6
Rajan’s age = 2
5. 6 ten rupee notes and 2 twenty rupee notes

20. ACTIVITY 3
1. 24 girls and 20 boys
2. 3/10
3. Table’s price = Rs 2000
chair’s price = Rs 500
4. He deposited Rs 3000 on the first and Rs 4000
on the other bank
5. Manu’s age is 12 and Mridula’s age is 16

21. ACTIVITY 4
1. Rs 4 for a pen and Rs 7 for a notebook
2. Rs 2 for a pencil and Rs 5 for a pen
3. Small can contains 2 liter and large can contains
5 liter
4. First number is 7 and second number is 5
5. There are 7 autorikshaws and 12 bikes
6. The number is 47

22. Prepared by
Naseera P P