Bobby, Luis and John had 238 buttons. After Bobby used 10 buttons and Luis used
37 of her buttons, Bobby had four times as many buttons left as Luis. John bought another 17 buttons, he had thrice the number of buttons Luis had left. How many buttons did John have at first?
| |
Bobby |
Luis |
John |
Total |
| Before |
16 u + 10 |
7 u |
12 u - 17 |
238 |
| Change |
- 10 |
- 3 u |
+ 17 |
|
| After |
16 u |
4 u |
12 u |
|
Comparing Bobby
and Luis in the end |
4 |
1 |
|
|
Comparing John
and Luis in the end |
|
1 |
3 |
|
Number of buttons that Bobby had in the end
= 4 x 4 u
= 16 u
Number of buttons that John had in the end
= 3 x 4 u
= 12 u
Total number of buttons at first
= 16 u + 10 + 7 u + 12 u - 17
= 35 u - 7
35 u - 7 = 238
35 u = 238 + 7
35 u = 245
1 u = 245 ÷ 35 = 7
Number of buttons that John had at first
= 12 u - 17
= 12 x 7 - 17
= 84 - 17
= 67
Answer(s): 67
