Question

the age of the father is twice the sum of the age of his two children after 20 years his age will be equal to the sum at the age of his children find the age of his father

Answer 1

Let the fathers age be x yrs
the sum of ages of 2 children be (a+b)yrs
acc to 1st condition
x=2(a+b)=2a+2b.....(1)
acc to 2nd condition
x+20=a+20+b+20
x+20=a+b+40
x=a+b+20.....(2)
equating (1) & (2)
a+b=20
sub this in(1)
x=40
therefore the fathers age is 40 yrs.