Xuan and Shiyun collected stamps. Xuan gave 25% of her stamps to Shiyun. As a result, Shiyun's stamps increased by 80%. If Xuan had 108 stamps left, find the total number of stamps the two girls had at first.
| |
Xuan |
Shiyun |
Comparing the change
in Shiyun's stamps |
| Before |
4x4 =
16 u |
|
5x1 =
5 u |
| Change |
- 1x4 =
- 4 u |
+ 1x4 =
+ 4 u |
+ 4x1 =
+ 4 u |
| After |
3x4 =
12 u |
|
9x1 =
9 u |
25% =
25100 =
14 80% =
80100 =
45 The number of stamps that Xuan gave to Shiyun is repeated. Make the number of stamps that Xuan gave to Shiyun the same. LCM of 1 and 4 is 4.
Number of stamps that Xuan had in the end = 12 u
12 u = 108
1 u = 108 ÷ 12 = 9
Number of stamps that Xuan and Shiyun had at first
= 16 u + 5 u
= 21 u
= 21 x 9
= 189
Answer(s): 189
