A collection of quarters, dimes, and nickels is worth $5.00. If the ratio of quarters to dimes is 2:4:7, how many quarters are there ?

8 quarters

Explanation:

Let's look at the ratio first off.

2 quarters: 4 dimes: 7 nickels

Let's write it in terms of money

50 cents of quarters: 40 cents of dimes: 35 cents of nickels

If we add up all the cents then we get $1.25

Then, if we divide $5 by $1.25 we get 4.

You should then multiply the original ratio by 4:

8 quarters: 16 dimes: 28 nickels

Let's check this by turning it to money:

$2: $1.60: $1.4

This all adds up to $5

Therefore your answer is 8 quarters.

Hope this helps!

- Kay