Jerry was 1/3 as young as his grandfather 15 years ago. If the sum of their ages is 110, how old is Jerry's grandfather?

1 Answer
Apr 26, 2017

75 years

Explanation:

Let grandfather's age was x years 15 years ago. So Jerry's age was x/3x3 years 15 years ago.

Hence 15 years ago sum of their's age was 110 - 15*2 = 80 years.

So as per questions, x + x/3 = 80x+x3=80

rArr [3x+x]/3 = 803x+x3=80

rArr (4x)/3 = 804x3=80

rArr x = 80xx3/4 = 60x=80×34=60

Therefore 15 years ago grandfather's age was 60 years.

Now grandfather's age is 60 + 15 = 75 years.