Bag B contains 50-cent coins and Bag C contains 20-cent coins. There are 21 more coins in Bag C than in Bag B. The amount of money in Bag B is 240¢ more than the amount of money in Bag C. How many total coins are there?
| |
Bag B |
Bag C |
| Number |
1 u |
1 u + 21 |
| Value |
50¢ |
20¢ |
| Total value |
50 u |
20 u + 420 |
Total value of 50¢ coins in Bag B
= 50 x 1 u
= 50 u
Total value of 20¢ coins in Bag C
= 20 x (1 u + 21)
= 20 u + 420
The amount in Bag B is 240¢ more than Bag C. If another 240¢ is added into Bag C, both Bag B and Bag C will have the same amounts of money.
50 u = 20 u + 420 + 240
50 u - 20 u = 420 + 240
30 u = 660
1 u = 660 ÷ 30 = 22
Total number of coins
= 1 u + (1 u + 21)
= 2 u + 21
= 2 x 22 + 21
= 44 + 21
= 65
Answer(s): 65
