Question

Kevin is 3 years older than Daniel. Two years ago, Kevin was 4 times as old as Daniel. How old is Daniel now

Answer 1

k = Kevin
d = Daniel

k = 3 + d;
k - 2 = 4( d - 2 );
We have 3 + d -  2 = 4d - 8;
Then, d + 1 = 4d - 8;
9 = 3d;
d = 3.
Finally, k = 6 years.