Xuan bought some buttons. She gave
16 of the buttons to her sister and sold
56 of the remaining buttons. After that, she bought another 62 buttons and had the same number of buttons that she bought at first. How many buttons did Xuan buy at first?
Her sister |
Remaining buttons |
Bought buttons |
Total |
1x6 = 6 u |
5x6 = 30 u |
|
6x6 = 36 u |
|
Sold |
Left |
|
|
|
5x5 |
1x5 |
|
|
6 u |
25 u |
5 u |
62 |
|
The remaining number of buttons before Xuan bought another 62 buttons is repeated. Make the remaining number of buttons the same. LCM of 5 and 6 is 30.
Total number of buttons at first = 36 u
Number of buttons that Xuan had left and bought after that = 5 u + 62
36 u = 5 u + 62
36 u - 5 u = 62
31 u = 62
1 u = 62 ÷ 31 = 2
Total number of buttons at first
= 36 u
= 36 x 2
= 72
Answer(s): 72