Sarah and Kylie collected buttons. Kylie gave 80% of her buttons to Sarah. As a result, Sarah's buttons increased by 40%. If Sarah had 98 buttons left, find the total number of buttons the two girls had at first.
| |
Comparing the change
in Kylie's buttons |
Kylie |
Sarah |
| Before |
5x1 =
5 u |
|
5x2 =
10 u |
| Change |
- 4x1 =
- 4 u |
- 2x2 =
- 4 u |
+ 2x2 =
+ 4 u |
| After |
1x1 =
1 u |
|
7x2 =
14 u |
80% =
80100 =
45 40% =
40100 =
25 The number of buttons that Sarah gave to Kylie is repeated. Make the number of buttons that Sarah gave to Kylie the same. LCM of 2 and 4 is 4.
Number of buttons that Sarah had in the end = 14 u
14 u = 98
1 u = 98 ÷ 14 = 7
Number of buttons that Kylie and Sarah had at first
= 5 u + 10 u
= 15 u
= 15 x 7
= 105
Answer(s): 105
