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

Let K = Kevin's current age and D = Daniel's current age.

From the problem:
1) K = 3D
2) K − 4 = 5(D − 4)

Substitute (1) into (2):
3D − 4 = 5D − 20
16 = 2D → D = 8

Thus K = 3D = 3·8 = 24.

Kevin is 24 years old now.