Sabrina and Emma collected cards. Sabrina gave 40% of her cards to Emma. As a result, Emma's cards increased by 80%. If Sabrina had 42 cards left, find the total number of cards the two girls had at first.
| |
Sabrina |
Emma |
Comparing the change
in Emma's cards |
| Before |
5x2 =
10 u |
|
5x1 =
5 u |
| Change |
- 2x2 =
- 4 u |
+ 2x2 =
+ 4 u |
+ 4x1 =
+ 4 u |
| After |
3x2 =
6 u |
|
9x1 =
9 u |
40% =
40100 =
25 80% =
80100 =
45 The number of cards that Sabrina gave to Emma is repeated. Make the number of cards that Sabrina gave to Emma the same. LCM of 2 and 4 is 4.
Number of cards that Sabrina had in the end = 6 u
6 u = 42
1 u = 42 ÷ 6 = 7
Number of cards that Sabrina and Emma had at first
= 10 u + 5 u
= 15 u
= 15 x 7
= 105
Answer(s): 105
