Bottle R contains 20-cent coins and Bottle S contains 5-cent coins. There are 40 more coins in Bottle S than in Bottle R. The amount of money in Bottle R is 130¢ more than the amount of money in Bottle S. How many total coins are there?
|
Bottle R |
Bottle S |
Number |
1 u |
1 u + 40 |
Value |
20¢ |
5¢ |
Total value |
20 u |
5 u + 200 |
Total value of 20¢ coins in Bottle R
= 20 x 1 u
= 20 u
Total value of 5¢ coins in Bottle S
= 5 x (1 u + 40)
= 5 u + 200
The amount in Bottle R is 130¢ more than Bottle S. If another 130¢ is added into Bottle S, both Bottle R and Bottle S will have the same amounts of money.
20 u = 5 u + 200 + 130
20 u - 5 u = 200 + 130
15 u = 330
1 u = 330 ÷ 15 = 22
Total number of coins
= 1 u + (1 u + 40)
= 2 u + 40
= 2 x 22 + 40
= 44 + 40
= 84
Answer(s): 84