Jar D contains 50-cent coins and Jar E contains 10-cent coins. There are 12 more coins in Jar E than in Jar D. The amount of money in Jar D is 280¢ more than the amount of money in Jar E. How many total coins are there?
| |
Jar D |
Jar E |
| Number |
1 u |
1 u + 12 |
| Value |
50¢ |
10¢ |
| Total value |
50 u |
10 u + 120 |
Total value of 50¢ coins in Jar D
= 50 x 1 u
= 50 u
Total value of 10¢ coins in Jar E
= 10 x (1 u + 12)
= 10 u + 120
The amount in Jar D is 280¢ more than Jar E. If another 280¢ is added into Jar E, both Jar D and Jar E will have the same amounts of money.
50 u = 10 u + 120 + 280
50 u - 10 u = 120 + 280
40 u = 400
1 u = 400 ÷ 40 = 10
Total number of coins
= 1 u + (1 u + 12)
= 2 u + 12
= 2 x 10 + 12
= 20 + 12
= 32
Answer(s): 32
