Mary had 60 more buttons than Nora. After Mary gave away
15 of her buttons and Nora gave away
34 of her buttons, Nora had 169 less buttons than Mary. How many buttons did Mary have at first?
| |
Mary |
Nora |
Comparing Mary and
Nora at first |
60 more |
|
| Before |
5x4 |
+ 60 |
4x5 |
| Change |
- 1x4 |
- 12 |
- 3x5 |
| After |
4x4 |
+ 48 |
1x5 |
Comparing Mary and
Nora in the end |
|
169 less |
| |
Mary |
Nora |
| Before |
20 u + 60 |
20 u |
| Change |
- 4 u - 12 |
- 15 u |
| After |
16 u + 48 |
5 u |
15 x 60 = 12
60 - 12 = 48
Nora had 169 less buttons than Mary in the end. So, if Nora had another 169 buttons in the end, the number of buttons that Nora and Mary each had would be the same.
16 u + 48 = 5 u + 169
16 u - 5 u = 169 - 48
11 u = 121
1 u = 121 ÷ 11 = 11
Number of buttons that Mary had at first
= 20 u + 60
= 20 x 11 + 60
= 220 + 60
= 280
Answer(s): 280
