Coin Box W contains 20-cent coins and Coin Box X contains 5-cent coins. There are 19 more coins in Coin Box X than in Coin Box W. The amount of money in Coin Box W is 355¢ more than the amount of money in Coin Box X. How many total coins are there?
| |
Coin Box W |
Coin Box X |
| Number |
1 u |
1 u + 19 |
| Value |
20¢ |
5¢ |
| Total value |
20 u |
5 u + 95 |
Total value of 20¢ coins in Coin Box W
= 20 x 1 u
= 20 u
Total value of 5¢ coins in Coin Box X
= 5 x (1 u + 19)
= 5 u + 95
The amount in Coin Box W is 355¢ more than Coin Box X. If another 355¢ is added into Coin Box X, both Coin Box W and Coin Box X will have the same amounts of money.
20 u = 5 u + 95 + 355
20 u - 5 u = 95 + 355
15 u = 450
1 u = 450 ÷ 15 = 30
Total number of coins
= 1 u + (1 u + 19)
= 2 u + 19
= 2 x 30 + 19
= 60 + 19
= 79
Answer(s): 79
