Adam had 91 dollars. If he spent 21 dollars on new books, what is the ratio of money he still has to money he’s spent?

The answer is 10:3 but I need a simple explanation on how! Please help!

Thanks!

Respuesta :

Step-by-step explanation:

ratio of money he has to money he's

used

70 : 21

so 70:21 is same as 70/21 = 10/3