Daniel and Cody had 27 cookies altogether. After Daniel ate ¹₃ of his cookies and Cody ate 9 cookies, the number of cookies Cody had left was thrice the number of cookies Daniel had left. How many more cookies did Cody have than Daniel at first?

	Daniel	Cody	Total
Before	3 u	6 u + 9	27
Change	- 1 u	- 9
After	2 u
Comparing Daniel and Cody in the end	1x2 = 2 u	3x2 = 6 u

The number of cookies that Daniel had in the end is the same. Make the number of cookies that Daniel had in the end the same.  LCM of 2 and 1 is 2.

Total number of cookies at first
= 3 u + 6 u + 9
= 9 u + 9

9 u + 9 = 27
9 u = 27 - 9
9 u = 18 

1 u = 18 ÷ 9 = 2

Number of cookies that Daniel had at first
= 3 u
= 3 x 2
= 6

Number of cookies that Cody had at first
= 27 - 6
= 21

Number of cookies that Cody had more than Daniel at first
= 21 - 6
= 15

Answer(s): 15