Question

Jamal was counting the coins in his bank. He found

that he had 70 coins, which totaled $13.30. If he
only had quarters and dimes, how many of each coin
did he have?

Answer 1

Jamal had 42 quarters and 28 dimes, with 70 coins totaling $13.30.

Step-by-step explanation:

The student asked to determine how many quarters and dimes Jamal had if he had 70 coins in total which amounted to $13.30 and he only had quarters and dimes. Let's define Q as the number of quarters and D as the number of dimes. Therefore, we have two equations based on the information given:
Q + D = 70 (1)
0.25Q + 0.10D = 13.30 (2)
To solve these equations, we can use substitution or elimination. For simplicity, we'll multiply equation (2) by 100 to remove decimals, which gives us 25Q + 10D = 1330. Then, we can multiply the first equation by 10, 10Q + 10D = 700, and subtract it from the modified equation (2) to eliminate D:
15Q = 630
Dividing both sides by 15 gives us Q = 42. Now we plug in the value of Q into equation (1) to find D:
42 + D = 70
D = 70 - 42
D = 28
So, Jamal had 42 quarters and 28 dimes.