Coin Box R contains only 50-cent coins and Coin Box S contains only 5-cent coins. There are 15 more coins in Coin Box S than in Coin Box R. The amount of money in Coin Box R is $3.30 more than the amount of money in Coin Box S. Find the total amount of money in both coin boxes.
|
Coin Box R |
Coin Box S |
Number |
1 u |
1 u + 15 |
Value |
50¢ |
5¢ |
Total value |
50 u |
5 u + 75 |
$1 = 100¢
$3.30 = 330¢
Total value of 50¢ coins in Coin Box R
= 50 x 1 u
= 50 u
Total value of 5¢ coins in Coin Box S
= 5(1 u + 15)
= 5 u + 75
The amount of money in Coin Box R is $3.30 more than the amount of money in Coin Box S. If another 330¢ is added into Coin Box S, the total value of coins in Coin Box R and Coin Box S will be the same.
50 u = 5 u + 75 + 330
50 u - 5 u = 405
45 u = 405
1 u = 405 ÷ 45 = 9
Total amount in both coin boxes
= 50 u + (5 u + 75)
= 55 u + 75
= (55 x 9) + 75
= 495 + 75
= 570¢
570¢ = $5.70
Answer(s): $5.70