Bottle D contains 20-cent coins and Bottle E contains 5-cent coins. There are 29 more coins in Bottle E than in Bottle D. The amount of money in Bottle D is 140¢ more than the amount of money in Bottle E. How many total coins are there?
| |
Bottle D |
Bottle E |
| Number |
1 u |
1 u + 29 |
| Value |
20¢ |
5¢ |
| Total value |
20 u |
5 u + 145 |
Total value of 20¢ coins in Bottle D
= 20 x 1 u
= 20 u
Total value of 5¢ coins in Bottle E
= 5 x (1 u + 29)
= 5 u + 145
The amount in Bottle D is 140¢ more than Bottle E. If another 140¢ is added into Bottle E, both Bottle D and Bottle E will have the same amounts of money.
20 u = 5 u + 145 + 140
20 u - 5 u = 145 + 140
15 u = 285
1 u = 285 ÷ 15 = 19
Total number of coins
= 1 u + (1 u + 29)
= 2 u + 29
= 2 x 19 + 29
= 38 + 29
= 67
Answer(s): 67
