Question

A collection of coins contains 15 pennies, 12 dimes, and 7 quarters. What is the percentage of pennies in the collection? Express your answer to two significant figures and include the appropriate units.

Answer 1

For this problem, let us first determine the total amount of the accumulation of the collection of coins and the total number of coins. Each penny values to 1. A dime is to 10, and a quarter would be 25. There are 15 pennies, 12 dimes, and 7 quarters. So the equation would be:

15 (1) + 12 (10) + 7 (25) = total amount

Let's solve.

15 + 120 + 175 = total amount
135 + 173 = total amount
308 = total amount

For the total number of coins, it goes like this:
15 + 12 + 7 = total number of coins
Solve

27 + 7 = total number of coins
34 = total number of coins

Since 100 pennies or 10 dimes or 4 quarters would equal to 1 dollar, the total amount would be 3 dollars and 8 cents or simply $3.08 with the total number of coins as 34.

To get percentage, simply divide 15 with the total number of coins which is 34 and multiply it by a 100. It will look like this:
(15/34) x 100 = percentage
solve
00.4411764 x 100 = percentage
44.11764% = percentage
let us round it off to the nearest hundredths
44.12% = percentage

The percentage of pennies in the collection would be 44.12%