Betty bought some buttons. She gave
14 of the buttons to her cousin and sold
25 of the remaining buttons. After that, she bought another 66 buttons and had the same number of buttons that she bought at first. How many buttons did Betty buy at first?
| Her cousin |
Remaining buttons |
Bought buttons |
Total |
1x5 =
5 u |
3x5 =
15 u |
|
4x5 =
20 u |
| |
Sold |
Left |
|
|
| |
2x3 |
3x3 |
|
|
| 5 u |
6 u |
9 u |
66 |
|
The remaining number of buttons before Betty bought another 66 buttons is repeated. Make the remaining number of buttons the same. LCM of 3 and 5 is 15.
Total number of buttons at first = 20 u
Number of buttons that Betty had left and bought after that = 9 u + 66
20 u = 9 u + 66
20 u - 9 u = 66
11 u = 66
1 u = 66 ÷ 11 = 6
Total number of buttons at first
= 20 u
= 20 x 6
= 120
Answer(s): 120
