Acollection 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.

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%