Riordan and Vincent had 73 wafers altogether. After Riordan ate ¹₆ of his wafers and Vincent ate 10 wafers, the number of wafers Vincent had left was thrice the number of wafers Riordan had left. How many more wafers did Vincent have than Riordan at first?

	Riordan	Vincent	Total
Before	6 u	15 u + 10	73
Change	- 1 u	- 10
After	5 u
Comparing Riordan and Vincent in the end	1x5 = 5 u	3x5 = 15 u

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

Total number of wafers at first
= 6 u + 15 u + 10
= 21 u + 10

21 u + 10 = 73
21 u = 73 - 10
21 u = 63 

1 u = 63 ÷ 21 = 3

Number of wafers that Riordan had at first
= 6 u
= 6 x 3
= 18

Number of wafers that Vincent had at first
= 73 - 18
= 55

Number of wafers that Vincent had more than Riordan at first
= 55 - 18
= 37

Answer(s): 37