Emma bought some coins. She gave
16 of the coins to her sister and sold
34 of the remaining coins. After that, she bought another 57 coins and had the same number of coins that she bought at first. How many coins did Emma buy at first?
| Her sister |
Remaining coins |
Bought coins |
Total |
1x4 =
4 u |
5x4 =
20 u |
|
6x4 =
24 u |
| |
Sold |
Left |
|
|
| |
3x5 |
1x5 |
|
|
| 4 u |
15 u |
5 u |
57 |
|
The remaining number of coins before Emma bought another 57 coins is repeated. Make the remaining number of coins the same. LCM of 5 and 4 is 20.
Total number of coins at first = 24 u
Number of coins that Emma had left and bought after that = 5 u + 57
24 u = 5 u + 57
24 u - 5 u = 57
19 u = 57
1 u = 57 ÷ 19 = 3
Total number of coins at first
= 24 u
= 24 x 3
= 72
Answer(s): 72
