31
The ages of two persons differ by 20 years. If 5 years ago, the elder one be 5 times as old as the younger one, their present ages (in years) are respectively
- A20,20
- B20,10
- C25,15
- D30,10
Correct answer: D
Log in or create a free account to reply and vote.
0
CCommunity
30,10
NA
NA
0
CCommunity
Solution:
Let us take the age of elder person as 'x' and the age of younger person as 'y'.
Given: x - y = 20
x = 20 + y
Five years ago, the elder one is 5 times as old as the younger person. So,
(x -5) = 5(y - 5)
x - 5 = 5y - 25
x - 5y = -25 + 5
x - 5y = -20
Substituting x here we have,
20 + y - 5y = -20
-4y = -20 -20
-4y = -40
y = 10
and x = 20 + 10 = 30
So, x = 30 and y = 10
The correct option is D). 30,10
Let us take the age of elder person as 'x' and the age of younger person as 'y'.
Given: x - y = 20
x = 20 + y
Five years ago, the elder one is 5 times as old as the younger person. So,
(x -5) = 5(y - 5)
x - 5 = 5y - 25
x - 5y = -25 + 5
x - 5y = -20
Substituting x here we have,
20 + y - 5y = -20
-4y = -20 -20
-4y = -40
y = 10
and x = 20 + 10 = 30
So, x = 30 and y = 10
The correct option is D). 30,10