Rolls are being prepared to go to grocery stores. Divide 72 rolls into 2 groups so the ratio is 3 to 5.

To do this, nice it to add 3 and 5, then divide 72 by the result of sum 3 and 5. Finally multiply it by 3 and by 5 to get the result.

Lets do this

3+5=8

72:8=9 - number of rolls in 1 "unit"

9*3=27 - first group

9*5=45 - second group