Roshel and Lucy have some wafers each. If Roshel gives Lucy 18 wafers, Roshel will have ⁴₇ as many wafers as Lucy. If Roshel gives Lucy 7 wafers, they will have an equal number of wafers. How many wafers does Lucy have at first?

	Case 1		Case 2
	Roshel	Lucy	Roshel	Lucy
Before	4 u + 18	7 u - 18	5.5 u + 7	5.5 u - 7
Change	- 18	+ 18	- 7	+ 7
After	4 u	7 u	5.5 u	5.5 u

Total number of wafers that Roshel and Lucy have
= 4 u + 7 u
= 11 u 

Number of wafers that Roshel and Lucy each has in the end is the same.

Number of wafers that Roshel and Lucy each has in the end in Case 2
= 11 u ÷ 2
= 5.5 u

Number of wafers that Roshel had at first is the same in Case 1 and Case 2.

5.5 u + 7 = 4 u + 18
5.5 u - 4 u = 18 - 7
0.5 u = 11

1 u = 11 ÷ 0.5 = 22

Number of wafers that Lucy has
= 7 u - 18
= 7 x 22 - 18
= 154 - 18
= 136

Answer(s): 136