Bag J contains 50-cent coins and Bag K contains 20-cent coins. There are 40 more coins in Bag K than in Bag J. The amount of money in Bag J is 10¢ more than the amount of money in Bag K. How many total coins are there?
| |
Bag J |
Bag K |
| Number |
1 u |
1 u + 40 |
| Value |
50¢ |
20¢ |
| Total value |
50 u |
20 u + 800 |
Total value of 50¢ coins in Bag J
= 50 x 1 u
= 50 u
Total value of 20¢ coins in Bag K
= 20 x (1 u + 40)
= 20 u + 800
The amount in Bag J is 10¢ more than Bag K. If another 10¢ is added into Bag K, both Bag J and Bag K will have the same amounts of money.
50 u = 20 u + 800 + 10
50 u - 20 u = 800 + 10
30 u = 810
1 u = 810 ÷ 30 = 27
Total number of coins
= 1 u + (1 u + 40)
= 2 u + 40
= 2 x 27 + 40
= 54 + 40
= 94
Answer(s): 94
