Erika had 100 more buttons than Joelle. After Erika gave away
15 of her buttons and Joelle gave away
34 of her buttons, Joelle had 190 less buttons than Erika. How many buttons did Erika have at first?
| |
Erika |
Joelle |
Comparing Erika and
Joelle at first |
100 more |
|
| Before |
5x4 |
+ 100 |
4x5 |
| Change |
- 1x4 |
- 20 |
- 3x5 |
| After |
4x4 |
+ 80 |
1x5 |
Comparing Erika and
Joelle in the end |
|
190 less |
| |
Erika |
Joelle |
| Before |
20 u + 100 |
20 u |
| Change |
- 4 u - 20 |
- 15 u |
| After |
16 u + 80 |
5 u |
15 x 100 = 20
100 - 20 = 80
Joelle had 190 less buttons than Erika in the end. So, if Joelle had another 190 buttons in the end, the number of buttons that Joelle and Erika each had would be the same.
16 u + 80 = 5 u + 190
16 u - 5 u = 190 - 80
11 u = 110
1 u = 110 ÷ 11 = 10
Number of buttons that Erika had at first
= 20 u + 100
= 20 x 10 + 100
= 200 + 100
= 300
Answer(s): 300
