Fiona and Hilda have some wafers each. If Fiona gives Hilda 20 wafers, Fiona will have ⁴₅ as many wafers as Hilda. If Fiona gives Hilda 4 wafers, they will have an equal number of wafers. How many wafers does Hilda have at first?

	Case 1		Case 2
	Fiona	Hilda	Fiona	Hilda
Before	4 u + 20	5 u - 20	4.5 u + 4	4.5 u - 4
Change	- 20	+ 20	- 4	+ 4
After	4 u	5 u	4.5 u	4.5 u

Total number of wafers that Fiona and Hilda have
= 4 u + 5 u
= 9 u 

Number of wafers that Fiona and Hilda each has in the end is the same.

Number of wafers that Fiona and Hilda each has in the end in Case 2
= 9 u ÷ 2
= 4.5 u

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

4.5 u + 4 = 4 u + 20
4.5 u - 4 u = 20 - 4
0.5 u = 16

1 u = 16 ÷ 0.5 = 32

Number of wafers that Hilda has
= 5 u - 20
= 5 x 32 - 20
= 160 - 20
= 140

Answer(s): 140