Andy, Sean and Lee had 100 buttons. After Andy used 2 buttons and Sean used
34 of her buttons, Andy had thrice as many buttons left as Sean. Lee bought another 12 buttons, he had four times the number of buttons Sean had left. How many buttons did Lee have at first?
| |
Andy |
Sean |
Lee |
Total |
| Before |
3 u + 2 |
4 u |
4 u - 12 |
100 |
| Change |
- 2 |
- 3 u |
+ 12 |
|
| After |
3 u |
1 u |
4 u |
|
Comparing Andy
and Sean in the end |
3 |
1 |
|
|
Comparing Lee
and Sean in the end |
|
1 |
4 |
|
Number of buttons that Andy had in the end
= 3 x 1 u
= 3 u
Number of buttons that Lee had in the end
= 4 x 1 u
= 4 u
Total number of buttons at first
= 3 u + 2 + 4 u + 4 u - 12
= 11 u - 10
11 u - 10 = 100
11 u = 100 + 10
11 u = 110
1 u = 110 ÷ 11 = 10
Number of buttons that Lee had at first
= 4 u - 12
= 4 x 10 - 12
= 40 - 12
= 28
Answer(s): 28
