Tin Can R contains 50-cent coins and Tin Can S contains 10-cent coins. There are 30 more coins in Tin Can S than in Tin Can R. The amount of money in Tin Can R is 420¢ more than the amount of money in Tin Can S. How many total coins are there?
| |
Tin Can R |
Tin Can S |
| Number |
1 u |
1 u + 30 |
| Value |
50¢ |
10¢ |
| Total value |
50 u |
10 u + 300 |
Total value of 50¢ coins in Tin Can R
= 50 x 1 u
= 50 u
Total value of 10¢ coins in Tin Can S
= 10 x (1 u + 30)
= 10 u + 300
The amount in Tin Can R is 420¢ more than Tin Can S. If another 420¢ is added into Tin Can S, both Tin Can R and Tin Can S will have the same amounts of money.
50 u = 10 u + 300 + 420
50 u - 10 u = 300 + 420
40 u = 720
1 u = 720 ÷ 40 = 18
Total number of coins
= 1 u + (1 u + 30)
= 2 u + 30
= 2 x 18 + 30
= 36 + 30
= 66
Answer(s): 66
