Question

The age of brother is 2 years more than his sister. The sum of their ages 5 years from now is 30 years. Find their present ages.

Answer 1

x+2=y

x+5+y+5=30

thus,x+y+10=30

x+y=20

x-y=-2

2x=18

x=9

y=11

the age of boy ,y=11

his sister's age=9