Shiyun and Irene collected stamps. Irene gave 75% of her stamps to Shiyun. As a result, Shiyun's stamps increased by 40%. If Shiyun had 63 stamps left, find the total number of stamps the two girls had at first.
| |
Comparing the change
in Irene's stamps |
Irene |
Shiyun |
| Before |
4x2 =
8 u |
|
5x3 =
15 u |
| Change |
- 3x2 =
- 6 u |
- 2x3 =
- 6 u |
+ 2x3 =
+ 6 u |
| After |
1x2 =
2 u |
|
7x3 =
21 u |
75% =
75100 =
34 40% =
40100 =
25 The number of stamps that Shiyun gave to Irene is repeated. Make the number of stamps that Shiyun gave to Irene the same. LCM of 2 and 3 is 6.
Number of stamps that Shiyun had in the end = 21 u
21 u = 63
1 u = 63 ÷ 21 = 3
Number of stamps that Irene and Shiyun had at first
= 8 u + 15 u
= 23 u
= 23 x 3
= 69
Answer(s): 69
