Kevin is 3 times as old as Daniel. 4 years ago, Kevin was 5 times as old as Daniel. How old is kevin now?

K=kevin age

d=daniel ae

k is 3 times d

k=3d

4 years ago (k-4 and d-4)

kevin was 5 times as old as dan

k-4=5 (d-4)

we have

k=3d

and

k-4=5 (d-4)

sub 3d for k in second euaiton

3d-4=5 (d-4)

3d-4=5d-20

minus 3d both sides

-4=2d-20

add 20 both sides

16=2d

divide 2

8=d

sub back

k=3d

k=3 (8)

k=24

kevin is 24