Home
Class 14
MATHS
The average of 20 numbers is 15 and the ...

The average of 20 numbers is 15 and the average of first five is 12.The average of the rest is

A

16

B

15

C

14

D

13

Text Solution

AI Generated Solution

The correct Answer is:
To find the average of the remaining numbers after the first five, we can follow these steps: ### Step 1: Calculate the sum of all 20 numbers. The average of 20 numbers is given as 15. The formula for average is: \[ \text{Average} = \frac{\text{Sum of numbers}}{\text{Total numbers}} \] From this, we can express the sum of the 20 numbers: \[ \text{Sum of 20 numbers} = \text{Average} \times \text{Total numbers} = 15 \times 20 = 300 \] ### Step 2: Calculate the sum of the first five numbers. The average of the first five numbers is given as 12. Using the same formula: \[ \text{Sum of first 5 numbers} = \text{Average} \times \text{Total numbers} = 12 \times 5 = 60 \] ### Step 3: Calculate the sum of the remaining 15 numbers. To find the sum of the remaining numbers, we subtract the sum of the first five numbers from the total sum of all numbers: \[ \text{Sum of remaining 15 numbers} = \text{Sum of 20 numbers} - \text{Sum of first 5 numbers} = 300 - 60 = 240 \] ### Step 4: Calculate the average of the remaining 15 numbers. Now, we can find the average of the remaining 15 numbers using the sum we just calculated: \[ \text{Average of remaining 15 numbers} = \frac{\text{Sum of remaining 15 numbers}}{\text{Total remaining numbers}} = \frac{240}{15} = 16 \] ### Final Answer: The average of the remaining numbers is **16**. ---
Promotional Banner

Similar Questions

Explore conceptually related problems

The average of 12 numbers is 15 and the average of the first two is 14. What is the average of the rest? (a) 15 (b) 15 1/5 (c) 14 (d) 14 1/5

The average of 9 numbers is 18. If the average of first five numbers is 19 and the average of last 5 numbers is 17, find the 5th number.

The average of 21 numbers is 12. The average of the first 11 numbers is 9 and the average of the last 11 numbers is 15. What is the value of the middle number ?