Luis and Tom had 41 wafers altogether. After Luis ate
15 of his wafers and Tom ate 7 wafers, the number of wafers Tom had left was thrice the number of wafers Luis had left. How many more wafers did Tom have than Luis at first?
| |
Luis |
Tom |
Total |
| Before |
5 u |
12 u + 7 |
41 |
| Change |
- 1 u |
- 7 |
|
| After |
4 u |
|
|
Comparing Luis and
Tom in the end |
1x4 =
4 u |
3x4 =
12 u |
|
The number of wafers that Luis had in the end is the same. Make the number of wafers that Luis had in the end the same. LCM of 4 and 1 is 4.
Total number of wafers at first
= 5 u + 12 u + 7
= 17 u + 7
17 u + 7 = 41
17 u = 41 - 7
17 u = 34
1 u = 34 ÷ 17 = 2
Number of wafers that Luis had at first
= 5 u
= 5 x 2
= 10
Number of wafers that Tom had at first
= 41 - 10
= 31
Number of wafers that Tom had more than Luis at first
= 31 - 10
= 21
Answer(s): 21
