Sarah and Marion collected pens. Marion gave 80% of her pens to Sarah. As a result, Sarah's pens increased by 10%. If Sarah had 264 pens left, find the total number of pens the two girls had at first.
| |
Comparing the change
in Marion's pens |
Marion |
Sarah |
| Before |
5x1 =
5 u |
|
10x4 =
40 u |
| Change |
- 4x1 =
- 4 u |
- 1x4 =
- 4 u |
+ 1x4 =
+ 4 u |
| After |
1x1 =
1 u |
|
11x4 =
44 u |
80% =
80100 =
45 10% =
10100 =
110 The number of pens that Sarah gave to Marion is repeated. Make the number of pens that Sarah gave to Marion the same. LCM of 1 and 4 is 4.
Number of pens that Sarah had in the end = 44 u
44 u = 264
1 u = 264 ÷ 44 = 6
Number of pens that Marion and Sarah had at first
= 5 u + 40 u
= 45 u
= 45 x 6
= 270
Answer(s): 270
