Xuan and Min collected cards. Min gave 80% of her cards to Xuan. As a result, Xuan's cards increased by 20%. If Xuan had 120 cards left, find the total number of cards the two girls had at first.
| |
Comparing the change
in Min's cards |
Min |
Xuan |
| Before |
5x1 =
5 u |
|
5x4 =
20 u |
| Change |
- 4x1 =
- 4 u |
- 1x4 =
- 4 u |
+ 1x4 =
+ 4 u |
| After |
1x1 =
1 u |
|
6x4 =
24 u |
80% =
80100 =
45 20% =
20100 =
15 The number of cards that Xuan gave to Min is repeated. Make the number of cards that Xuan gave to Min the same. LCM of 1 and 4 is 4.
Number of cards that Xuan had in the end = 24 u
24 u = 120
1 u = 120 ÷ 24 = 5
Number of cards that Min and Xuan had at first
= 5 u + 20 u
= 25 u
= 25 x 5
= 125
Answer(s): 125
