Yen and Esther have some wafers each. If Yen gives Esther 18 wafers, Yen will have
12 as many wafers as Esther. If Yen gives Esther 2 wafers, they will have an equal number of wafers. How many wafers does Esther have at first?
| |
Case 1 |
Case 2 |
| |
Yen |
Esther |
Yen |
Esther |
| Before |
1 u + 18 |
2 u - 18 |
1.5 u + 2 |
1.5 u - 2 |
| Change |
- 18 |
+ 18 |
- 2 |
+ 2 |
| After |
1 u |
2 u |
1.5 u |
1.5 u |
Total number of wafers that Yen and Esther have
= 1 u + 2 u
= 3 u
Number of wafers that Yen and Esther each has in the end is the same.
Number of wafers that Yen and Esther each has in the end in Case 2
= 3 u ÷ 2
= 1.5 u
Number of wafers that Yen had at first is the same in Case 1 and Case 2.
1.5 u + 2 = 1 u + 18
1.5 u - 1 u = 18 - 2
0.5 u = 16
1 u = 16 ÷ 0.5 = 32
Number of wafers that Esther has
= 2 u - 18
= 2 x 32 - 18
= 64 - 18
= 46
Answer(s): 46
