Mary and Min collected buttons. Mary gave 25% of her buttons to Min. As a result, Min's buttons increased by 70%. If Mary had 168 buttons left, find the total number of buttons the two girls had at first.
| |
Mary |
Min |
Comparing the change
in Min's buttons |
| Before |
4x7 =
28 u |
|
10x1 =
10 u |
| Change |
- 1x7 =
- 7 u |
+ 1x7 =
+ 7 u |
+ 7x1 =
+ 7 u |
| After |
3x7 =
21 u |
|
17x1 =
17 u |
25% =
25100 =
14 70% =
70100 =
710 The number of buttons that Mary gave to Min is repeated. Make the number of buttons that Mary gave to Min the same. LCM of 1 and 7 is 7.
Number of buttons that Mary had in the end = 21 u
21 u = 168
1 u = 168 ÷ 21 = 8
Number of buttons that Mary and Min had at first
= 28 u + 10 u
= 38 u
= 38 x 8
= 304
Answer(s): 304
