Vanessa had 80 more buttons than Betty. After Vanessa gave away
25 of her buttons and Betty gave away
34 of her buttons, Betty had 90 less buttons than Vanessa. How many buttons did Vanessa have at first?
| |
Vanessa |
Betty |
Comparing Vanessa and
Betty at first |
80 more |
|
| Before |
5x4 |
+ 80 |
4x5 |
| Change |
- 2x4 |
- 32 |
- 3x5 |
| After |
3x4 |
+ 48 |
1x5 |
Comparing Vanessa and
Betty in the end |
|
90 less |
| |
Vanessa |
Betty |
| Before |
20 u + 80 |
20 u |
| Change |
- 8 u - 32 |
- 15 u |
| After |
12 u + 48 |
5 u |
25 x 80 = 32
80 - 32 = 48
Betty had 90 less buttons than Vanessa in the end. So, if Betty had another 90 buttons in the end, the number of buttons that Betty and Vanessa each had would be the same.
12 u + 48 = 5 u + 90
12 u - 5 u = 90 - 48
7 u = 42
1 u = 42 ÷ 7 = 6
Number of buttons that Vanessa had at first
= 20 u + 80
= 20 x 6 + 80
= 120 + 80
= 200
Answer(s): 200
