Tommy is
f years old. Ivan is six times as old as Tommy and Billy is 10 years younger than Ivan.
- Express Billy's age in terms of f.
- Tommy is 8 years old as of now. ln how many years' time will Billy be 4 times as old as Tommy?
(a)
Tommy's age =
f years
Ivan's age = 6
f years
Billy's age = (6
f - 10) years
(b)
f = 8
Difference in age remains unchanged.
Difference in age between Billy and Tommy
= (6
f - 10) -
f = 6
f -
f - 10
= 5
f - 10
= 5 x 8 - 10
= 30 years
Difference in the age when Billy will be 4 times as old as Tommy
= 4 u - 1 u
= 3 u
3 u = 30
1 u = 30 ÷ 3 = 10
Number of years' time so Billy will be 4 times as old as Tommy
= 10 - 8
= 2 years
Answer(s): (a) (6
f - 10) years; (b) 2 years
