Sarah and Mary collected stickers. Sarah gave 10% of her stickers to Mary. As a result, Mary's stickers increased by 80%. If Sarah had 360 stickers left, find the total number of stickers the two girls had at first.
| |
Sarah |
Mary |
Comparing the change
in Mary's stickers |
| Before |
10x4 =
40 u |
|
5x1 =
5 u |
| Change |
- 1x4 =
- 4 u |
+ 1x4 =
+ 4 u |
+ 4x1 =
+ 4 u |
| After |
9x4 =
36 u |
|
9x1 =
9 u |
10% =
10100 =
110 80% =
80100 =
45 The number of stickers that Sarah gave to Mary is repeated. Make the number of stickers that Sarah gave to Mary the same. LCM of 1 and 4 is 4.
Number of stickers that Sarah had in the end = 36 u
36 u = 360
1 u = 360 ÷ 36 = 10
Number of stickers that Sarah and Mary had at first
= 40 u + 5 u
= 45 u
= 45 x 10
= 450
Answer(s): 450
