Betty bought some cards. She gave
17 of the cards to her cousin and sold
25 of the remaining cards. After that, she bought another 187 cards and had the same number of cards that she bought at first. How many cards did Betty buy at first?
| Her cousin |
Remaining cards |
Bought cards |
Total |
1x5 =
5 u |
6x5 =
30 u |
|
7x5 =
35 u |
| |
Sold |
Left |
|
|
| |
2x6 |
3x6 |
|
|
| 5 u |
12 u |
18 u |
187 |
|
The remaining number of cards before Betty bought another 187 cards is repeated. Make the remaining number of cards the same. LCM of 6 and 5 is 30.
Total number of cards at first = 35 u
Number of cards that Betty had left and bought after that = 18 u + 187
35 u = 18 u + 187
35 u - 18 u = 187
17 u = 187
1 u = 187 ÷ 17 = 11
Total number of cards at first
= 35 u
= 35 x 11
= 385
Answer(s): 385
