At first, Paul, Jen and Glen had some chocolate bars in the ratio 7 : 5 : 6 respectively. Paul had 378 chocolate bars. Then he gave all his chocolate bars to Jen and Glen. After receiving the chocolate bars from Paul, Jen and Glen had the same number of chocolate bars. How many chocolate bars did Jen receive from Paul?

	Paul	Jen	Glen	Total
Before	7x1 = 7 u	5x1 = 5 u	6x1 = 6 u	18x1 = 18 u
Change	- 7 u	+ 7 u
After	0	1x9 = 9 u	1x9 = 9 u	2x9 = 18 u

The total number of chocolate bars remains unchanged. Make the total number of chocolate bars the same.  LCM of 2 and 18 is 18.

Total number of chocolate bars = 18 u

Number of chocolate bars that Jen had in the end 
= 18 u ÷ 2
= 9 u

Number of chocolate bars that Paul had at first = 7 u 

7 u = 378

1 u = 378 ÷ 7 = 54

Number of chocolate bars that Jen received from Paul
= 9 u - 5 u
= 4 u
= 4 x 54
= 216

Answer(s): 216