Tiffany bought some marbles. She gave
15 of the marbles to her brother and sold
56 of the remaining marbles. After that, she bought another 156 marbles and had the same number of marbles that she bought at first. How many marbles did Tiffany buy at first?
| Her brother |
Remaining marbles |
Bought marbles |
Total |
1x3 =
3 u |
4x3 =
12 u |
|
5x3 =
15 u |
| |
Sold |
Left |
|
|
| |
5x2 |
1x2 |
|
|
| 3 u |
10 u |
2 u |
156 |
|
The remaining number of marbles before Tiffany bought another 156 marbles is repeated. Make the remaining number of marbles the same. LCM of 4 and 6 is 12.
Total number of marbles at first = 15 u
Number of marbles that Tiffany had left and bought after that = 2 u + 156
15 u = 2 u + 156
15 u - 2 u = 156
13 u = 156
1 u = 156 ÷ 13 = 12
Total number of marbles at first
= 15 u
= 15 x 12
= 180
Answer(s): 180
