Question 499320
Let
Present age of a = a
Present age of b = b

a present age is double the age of b
a=2b
sum of thier ages
a+b=63

put the value of a in above equation
2b+b=63
3b=63
b=63/3
b=21

a=2b=2*21=42

a is 42 and b is 21 years old