Five years ago, a father was 3 times as old as his son, now their combined ages amount to 110years. thus, the present age of the father is
A
75 years
B
60 years
C
98 years
D
80 years
E
105 years
Verified Correct Answer: D.
Step-by-Step Mathematical Solution
Let the present ages of father be x and son = y
five years ago, father = x - 5
son = y - 5
x - 5 = 3(y - 5)
x - 5 = 3y - 15
x - 3y = -15 + 5 = -10 ......(i)
x + y = 110......(ii)
eqn(ii) - eqn(i)
4y = 120
y = 30
sub for y = 30 in eqn(i)
x -10 = 3(30)
x -10 = 90
x = 80
Source: Myschool Past Questions Archive (Record #32694)