David and Riordan had 48 croissants altogether. After David ate ¹₆ of his croissants and Riordan ate 6 croissants, the number of croissants Riordan had left was thrice the number of croissants David had left. How many more croissants did Riordan have than David at first?

	David	Riordan	Total
Before	6 u	15 u + 6	48
Change	- 1 u	- 6
After	5 u
Comparing David and Riordan in the end	1x5 = 5 u	3x5 = 15 u

The number of croissants that David had in the end is the same. Make the number of croissants that David had in the end the same.  LCM of 5 and 1 is 5.

Total number of croissants at first
= 6 u + 15 u + 6
= 21 u + 6

21 u + 6 = 48
21 u = 48 - 6
21 u = 42 

1 u = 42 ÷ 21 = 2

Number of croissants that David had at first
= 6 u
= 6 x 2
= 12

Number of croissants that Riordan had at first
= 48 - 12
= 36

Number of croissants that Riordan had more than David at first
= 36 - 12
= 24

Answer(s): 24