Emma bought some marbles. She gave
14 of the marbles to her brother and sold
35 of the remaining marbles. After that, she bought another 28 marbles and had the same number of marbles that she bought at first. How many marbles did Emma buy at first?
| Her brother |
Remaining marbles |
Bought marbles |
Total |
1x5 =
5 u |
3x5 =
15 u |
|
4x5 =
20 u |
| |
Sold |
Left |
|
|
| |
3x3 |
2x3 |
|
|
| 5 u |
9 u |
6 u |
28 |
|
The remaining number of marbles before Emma bought another 28 marbles is repeated. Make the remaining number of marbles the same. LCM of 3 and 5 is 15.
Total number of marbles at first = 20 u
Number of marbles that Emma had left and bought after that = 6 u + 28
20 u = 6 u + 28
20 u - 6 u = 28
14 u = 28
1 u = 28 ÷ 14 = 2
Total number of marbles at first
= 20 u
= 20 x 2
= 40
Answer(s): 40
