The document provides 10 examples of average/mean calculation questions and their explanations. It covers calculating the average price, average speed, average of cubes, arithmetic mean, and average of ranges of consecutive and divisible numbers. The examples demonstrate different methods for finding the average, including using formulas like sum of terms divided by total terms or n(n+1)/2.

1. AVERAGE
QUESTIONS AND
ANSWERS

2. 1) 20 pens and 55 pencils were purchased for
Rs.600.If the average price of a pencil was Rs.2 ,
find the average price of a pen ?
Explanation:
Since average price of a pencil = Rs. 2
Therefore Price of 55 pencils = Rs.110 , Price of
20 pens =600-110 = 490
average price of a pen = 490/20 =24.5
Ans: 24.5

3. 2) A man walks 2500 metres in 40 minutes , 1000
metres in 30 minutes and 500 metres in 10 minutes.
Then what is the average speed for whole walking
distance ?
Explanation:
Average marks = (2500+1000+500) / (40+30+10) =
4000 / 80 = 50
Ans : 50

4. 3) Anil travels to a place 200 km away at an average
speed of 70 km/hr and returns at 32 km/hr. Find the
average speed for whole journey in km/hr ?
Explanation:
Average speed = 2xy/ x+y .
Average speed of given problem = (2*70*32) / 70+32
(140 *32) /102 = 4480/102 = 43.92
Average speed of given problem =43.92.
Ans: 43.92.

5. 4) Find the average of cubes of consecutive 10 natural
numbers ?
Explanation:
10(10+1)² / 4 = (110)²/4 = 12100 /4 = 3025
Average of cubes of consecutive n natural numbers=
n(n+1)² / 4.
Ans: 3025

6. 5) Find the arithmetic mean of 3 , 5 , 7 , 8 , 13 , 17 ,22
and x. Mean is 10 ,what should be the number in
place of x ?
Explanation:
Mean or average = (3+5+7+8+13+17+22+x) / 8 =10 --
---> (75 +x) /8 =10 -------> x = 80 -75 = 5.
Ans: 5

7. 6) Find the average of all the numbers between 5 to 25
, which are divisible by 3 ?
Explanation:
Average = ( 6+9+12+15+18+21+24) / 7 = 105 / 7 =15.
Ans: 15

8. 7) Find the average of consecutive 25 natural numbers
?
Explanation :
(25+1) / 2 = 26/2 = 13
Average of consecutive n natural numbers = (n+1)/2
Ans: 13

9. 8) Find the average of consecutive even numbers to
80 ?
Explanation :
Average = ((N/2)+1)
=(80/2)+1 = 40+1 = 41.
Ans : 41

10. 9) Find the average of consecutive natural numbers
from 20 to 80 ?
Explanation :
Average = (1st number + last number) / 2.
So Average of given numbers = (20+80) / 2 =100/2
=50.
Ans : 50

11. 10) Find the Average of first 50 naturals numbers ?
Explanation :
Sum of first n natural numbers = n(n+1)/2.
So (50*51)/2 =1275 , There fore Required average =
1275/50 = 25.5
Ans: 25.5

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