Warren and David shared some pens in the ratio of 3 : 8. After both each gave away 49 pens to their cousin, the ratio of the number of pens Warren had to the total number of pens left was 1 : 6. How many pens did the two boys have in the end?

	Warren	David	Difference
Before	3x4 = 12 u	8x4 = 32 u	5x4 = 20 u
Change	- 49	- 49
After	1x5 = 5 u	5x5 = 25 u	4x5 = 20 u

Number of pens that Warren and David each gave to their cousin is the same.

The difference in the number of pens at first and in the end between Warren and David remains unchanged.  Make the difference in the number of pens the same.  LCM of 5 and 4 is 20.

Number of pens that Warren gave to their cousin
= 12 u - 5 u
= 7 u

7 u = 49

1 u = 49 ÷ 7 = 7

Number of pens that the two boys had in the end
= 5 u + 25 u
= 30 u
= 30 x 7
= 210

Answer(s): 210