Question

the average age of you and your elder brother is 15. if your age is 12 year find the age of your brother​

Answer 1

answer:

cosider you as A and your elder brother as B

From given: (A+B)/2=15

A+B=15×2

A+B=30-------equation 1

Then,

A=12

substitute in equation 1,

12+B=30

B=30-12

B=18

brother age is 18 years.