Sarah had 105 more buttons than Eva. After Sarah gave away
15 of her buttons and Eva gave away
34 of her buttons, Eva had 172 less buttons than Sarah. How many buttons did Sarah have at first?
| |
Sarah |
Eva |
Comparing Sarah and
Eva at first |
105 more |
|
| Before |
5x4 |
+ 105 |
4x5 |
| Change |
- 1x4 |
- 21 |
- 3x5 |
| After |
4x4 |
+ 84 |
1x5 |
Comparing Sarah and
Eva in the end |
|
172 less |
| |
Sarah |
Eva |
| Before |
20 u + 105 |
20 u |
| Change |
- 4 u - 21 |
- 15 u |
| After |
16 u + 84 |
5 u |
15 x 105 = 21
105 - 21 = 84
Eva had 172 less buttons than Sarah in the end. So, if Eva had another 172 buttons in the end, the number of buttons that Eva and Sarah each had would be the same.
16 u + 84 = 5 u + 172
16 u - 5 u = 172 - 84
11 u = 88
1 u = 88 ÷ 11 = 8
Number of buttons that Sarah had at first
= 20 u + 105
= 20 x 8 + 105
= 160 + 105
= 265
Answer(s): 265
