Laps word problem

Question

Carmen swam 8 fewer laps than 3 times the number of laps Mario swam. They swam 72 to laps altogether. How many laps did Mario swim?

Answer 1

C - Carmens number of laps
M - Marios laps

1) C + M = 72 (together they swam 72 laps)
2) C = 3M - 8 (carmen swam 8 fewer laps than 3 times what mario swam. Can be tricky to change the words into this equation!)

plug equation 2, into equation 1

3M - 8 + M = 72, (add 8 to both sides)

4M = 80 (divide both sides by 4)

M = 20