Coin Box U contains 50-cent coins and Coin Box V contains 20-cent coins. There are 20 more coins in Coin Box V than in Coin Box U. The amount of money in Coin Box U is 320¢ more than the amount of money in Coin Box V. How many total coins are there?
|
Coin Box U |
Coin Box V |
Number |
1 u |
1 u + 20 |
Value |
50¢ |
20¢ |
Total value |
50 u |
20 u + 400 |
Total value of 50¢ coins in Coin Box U
= 50 x 1 u
= 50 u
Total value of 20¢ coins in Coin Box V
= 20 x (1 u + 20)
= 20 u + 400
The amount in Coin Box U is 320¢ more than Coin Box V. If another 320¢ is added into Coin Box V, both Coin Box U and Coin Box V will have the same amounts of money.
50 u = 20 u + 400 + 320
50 u - 20 u = 400 + 320
30 u = 720
1 u = 720 ÷ 30 = 24
Total number of coins
= 1 u + (1 u + 20)
= 2 u + 20
= 2 x 24 + 20
= 48 + 20
= 68
Answer(s): 68