Tiffany bought some stamps. She gave
15 of the stamps to her brother and sold
25 of the remaining stamps. After that, she bought another 156 stamps and had the same number of stamps that she bought at first. How many stamps did Tiffany buy at first?
| Her brother |
Remaining stamps |
Bought stamps |
Total |
1x5 =
5 u |
4x5 =
20 u |
|
5x5 =
25 u |
| |
Sold |
Left |
|
|
| |
2x4 |
3x4 |
|
|
| 5 u |
8 u |
12 u |
156 |
|
The remaining number of stamps before Tiffany bought another 156 stamps is repeated. Make the remaining number of stamps the same. LCM of 4 and 5 is 20.
Total number of stamps at first = 25 u
Number of stamps that Tiffany had left and bought after that = 12 u + 156
25 u = 12 u + 156
25 u - 12 u = 156
13 u = 156
1 u = 156 ÷ 13 = 12
Total number of stamps at first
= 25 u
= 25 x 12
= 300
Answer(s): 300
