Irene bought some stickers. She gave
15 of the stickers to her sister and sold
35 of the remaining stickers. After that, she bought another 51 stickers and had the same number of stickers that she bought at first. How many stickers did Irene buy at first?
| Her sister |
Remaining stickers |
Bought stickers |
Total |
1x5 =
5 u |
4x5 =
20 u |
|
5x5 =
25 u |
| |
Sold |
Left |
|
|
| |
3x4 |
2x4 |
|
|
| 5 u |
12 u |
8 u |
51 |
|
The remaining number of stickers before Irene bought another 51 stickers is repeated. Make the remaining number of stickers the same. LCM of 4 and 5 is 20.
Total number of stickers at first = 25 u
Number of stickers that Irene had left and bought after that = 8 u + 51
25 u = 8 u + 51
25 u - 8 u = 51
17 u = 51
1 u = 51 ÷ 17 = 3
Total number of stickers at first
= 25 u
= 25 x 3
= 75
Answer(s): 75
