If a bag contains 12 quarters, 6 dimes, and 18 nickles, what is the part-to-whole ratio of nickles to all coins?

18/36 or 1/2

Step-by-step explanation:

There are 18 nickels, which is the numerator.

You add all the numbers together to get the denominator, which is 12+6+18=36.

Then, you put the two values in a fraction - 18/36

and simplify, to get you 1/2.