Question

Kevin is 3 times as old as Daniel. 4 years ago, Kevin was 5 times as old as Daniel.

How old is Kevin now?

Answer 1

X is Kevin; Y is Dan

X = 3Y

X - 4 = 5(Y - 4)


3Y - 4 = 5(Y - 4)
3Y - 4 = 5Y - 20
+ 4 +4
4 cancels each other out.
3Y = 5Y - 16
- 5 -5
5 cancels each other out.
-2Y = -16
/2 /2
Y = 8

X = 3Y;
X = 3 x 8;

Thus,
X = 24;
Kevin(x) is 24