Question

A collection of dimes and nickels has a total value of two dollars and contains 31 coins. how many dimes are there in the collection?

13 dimes 9 dimes 11 dimes
7 dimes

Answer 1

Hi,

Answer: 9 dimes

Explanation:

Let's assume x the number of dimes

31-x the number of nickels

`10*x+5*(31-x)=200\\\\5x+155=200\\\\5x=45\\\\x=9\\\\`

Number of dimes: 9

Number of nickels=31-9=22

Proof:

9*10+22*5=90+110=200