father son age problem

It should be C) 35 and 15

fastest way is takinng option and calculate.
lilke from d ..if u subtract -- 5 , that will give their age..3 times...true and if u add five,father will be of 40 and son 20, So both codn satisfy.No need to calculate.

vivek.kapoor83 wrote:fastest way is takinng option and calculate.
lilke from d ..if u subtract -- 5 , that will give their age..3 times...true and if u add five,father will be of 40 and son 20, So both codn satisfy.No need to calculate.

Good one

imo:c

I am not getting this one

two equations I set up

f-5 = 3(s-5)
f=2s

How do you get the answer algebraically?

Let x be fathers present age and y be the sons present age

A father's age was three times that of his son five years ago:

x-5 = 3(y-5)
x-3y = -10 (1)

While five years hence the father will be twice as old as his son:

x+5 = 2(y+5)
x-2y = 5 (2)


Subtract 1 and 2:

x-3y = -10
x-2y = 5

-3y-(-2y) = -10 - 5

-y = -15

y =15

x=35

Hope this helps!