Bag R contains 20-cent coins and Bag S contains 10-cent coins. There are 11 more coins in Bag S than in Bag R. The amount of money in Bag R is 20¢ more than the amount of money in Bag S. How many total coins are there?
| |
Bag R |
Bag S |
| Number |
1 u |
1 u + 11 |
| Value |
20¢ |
10¢ |
| Total value |
20 u |
10 u + 110 |
Total value of 20¢ coins in Bag R
= 20 x 1 u
= 20 u
Total value of 10¢ coins in Bag S
= 10 x (1 u + 11)
= 10 u + 110
The amount in Bag R is 20¢ more than Bag S. If another 20¢ is added into Bag S, both Bag R and Bag S will have the same amounts of money.
20 u = 10 u + 110 + 20
20 u - 10 u = 110 + 20
10 u = 130
1 u = 130 ÷ 10 = 13
Total number of coins
= 1 u + (1 u + 11)
= 2 u + 11
= 2 x 13 + 11
= 26 + 11
= 37
Answer(s): 37
