Tiffany and Diana have some croissants each. If Tiffany gives Diana 37 croissants, Tiffany will have ¹₈ as many croissants as Diana. If Tiffany gives Diana 9 croissants, they will have an equal number of croissants. How many croissants does Diana have at first?

	Case 1		Case 2
	Tiffany	Diana	Tiffany	Diana
Before	1 u + 37	8 u - 37	4.5 u + 9	4.5 u - 9
Change	- 37	+ 37	- 9	+ 9
After	1 u	8 u	4.5 u	4.5 u

Total number of croissants that Tiffany and Diana have
= 1 u + 8 u
= 9 u 

Number of croissants that Tiffany and Diana each has in the end is the same.

Number of croissants that Tiffany and Diana each has in the end in Case 2
= 9 u ÷ 2
= 4.5 u

Number of croissants that Tiffany had at first is the same in Case 1 and Case 2.

4.5 u + 9 = 1 u + 37
4.5 u - 1 u = 37 - 9
0.5 u = 28

1 u = 28 ÷ 0.5 = 56

Number of croissants that Diana has
= 8 u - 37
= 8 x 56 - 37
= 448 - 37
= 411

Answer(s): 411