Question

The average of three numbers is 7 .If the average of first two numbers is 5 find the third number​

Answer 1

Answer:

Sum of 3 numbers = 7 × 3 = 21

Sum of 2 numbers = 2 × 5 = 10

so, third number = 21 - 10 = 11

Answer 2

sum of 3 number = 7 × 3 = 21

sum of 2 number = 2 × 5 = 10

third number = 21 - 10 = 11