Coin Box D contains 50-cent coins and Coin Box E contains 5-cent coins. There are 34 more coins in Coin Box E than in Coin Box D. The amount of money in Coin Box D is 640¢ more than the amount of money in Coin Box E. How many total coins are there?
| |
Coin Box D |
Coin Box E |
| Number |
1 u |
1 u + 34 |
| Value |
50¢ |
5¢ |
| Total value |
50 u |
5 u + 170 |
Total value of 50¢ coins in Coin Box D
= 50 x 1 u
= 50 u
Total value of 5¢ coins in Coin Box E
= 5 x (1 u + 34)
= 5 u + 170
The amount in Coin Box D is 640¢ more than Coin Box E. If another 640¢ is added into Coin Box E, both Coin Box D and Coin Box E will have the same amounts of money.
50 u = 5 u + 170 + 640
50 u - 5 u = 170 + 640
45 u = 810
1 u = 810 ÷ 45 = 18
Total number of coins
= 1 u + (1 u + 34)
= 2 u + 34
= 2 x 18 + 34
= 36 + 34
= 70
Answer(s): 70
