Julie and Xuan have some wafers each. If Julie gives Xuan 37 wafers, Julie will have
34 as many wafers as Xuan. If Julie gives Xuan 9 wafers, they will have an equal number of wafers. How many wafers does Xuan have at first?
| |
Case 1 |
Case 2 |
| |
Julie |
Xuan |
Julie |
Xuan |
| Before |
3 u + 37 |
4 u - 37 |
3.5 u + 9 |
3.5 u - 9 |
| Change |
- 37 |
+ 37 |
- 9 |
+ 9 |
| After |
3 u |
4 u |
3.5 u |
3.5 u |
Total number of wafers that Julie and Xuan have
= 3 u + 4 u
= 7 u
Number of wafers that Julie and Xuan each has in the end is the same.
Number of wafers that Julie and Xuan each has in the end in Case 2
= 7 u ÷ 2
= 3.5 u
Number of wafers that Julie had at first is the same in Case 1 and Case 2.
3.5 u + 9 = 3 u + 37
3.5 u - 3 u = 37 - 9
0.5 u = 28
1 u = 28 ÷ 0.5 = 56
Number of wafers that Xuan has
= 4 u - 37
= 4 x 56 - 37
= 224 - 37
= 187
Answer(s): 187
