Ratio Question (In the description)

Question

Sammy and David were selling water bottles to raise money for new football uniforms. Sammy sold 5 water bottles for every 3 water bottles David sold. Together they sold 160 water bottles. How many did each boy sell?

Answer 1

the ratio 5:3 means that, of every eight bottles sold, Sammy sold five, so he sold 5/8 of the 160 total.

Therefore Sammy sold 100 bottles.