Tommy, Valen and Pierre had 112 buttons. After Tommy used 23 buttons and Valen used
13 of her buttons, Tommy had four times as many buttons left as Valen. Pierre bought another 30 buttons, he had thrice the number of buttons Valen had left. How many buttons did Pierre have at first?
| |
Tommy |
Valen |
Pierre |
Total |
| Before |
8 u + 23 |
3 u |
6 u - 30 |
112 |
| Change |
- 23 |
- 1 u |
+ 30 |
|
| After |
8 u |
2 u |
6 u |
|
Comparing Tommy
and Valen in the end |
4 |
1 |
|
|
Comparing Pierre
and Valen in the end |
|
1 |
3 |
|
Number of buttons that Tommy had in the end
= 4 x 2 u
= 8 u
Number of buttons that Pierre had in the end
= 3 x 2 u
= 6 u
Total number of buttons at first
= 8 u + 23 + 3 u + 6 u - 30
= 17 u - 7
17 u - 7 = 112
17 u = 112 + 7
17 u = 119
1 u = 119 ÷ 17 = 7
Number of buttons that Pierre had at first
= 6 u - 30
= 6 x 7 - 30
= 42 - 30
= 12
Answer(s): 12
