Olivia bought some pens. She gave
17 of the pens to her sister and sold
34 of the remaining pens. After that, she bought another 66 pens and had the same number of pens that she bought at first. How many pens did Olivia buy at first?
| Her sister |
Remaining pens |
Bought pens |
Total |
1x2 =
2 u |
6x2 =
12 u |
|
7x2 =
14 u |
| |
Sold |
Left |
|
|
| |
3x3 |
1x3 |
|
|
| 2 u |
9 u |
3 u |
66 |
|
The remaining number of pens before Olivia bought another 66 pens is repeated. Make the remaining number of pens the same. LCM of 6 and 4 is 12.
Total number of pens at first = 14 u
Number of pens that Olivia had left and bought after that = 3 u + 66
14 u = 3 u + 66
14 u - 3 u = 66
11 u = 66
1 u = 66 ÷ 11 = 6
Total number of pens at first
= 14 u
= 14 x 6
= 84
Answer(s): 84
