David, Pierre and Mark shared a sum of money. The amount received by Pierre was ³₄ the amount of money received by Mark. After David had given $42 to Pierre and $27 to Mark, Pierre gave $2 to Mark. In the end, 3 of them had the same amount of money. Find the difference between the amount of money that David and Pierre had at first.

	David	Pierre	Mark
Before	3 u + 109	3 u	4 u
Change 1	- 42	+ 42
Change 2	- 27		+ 27
Change 3		- 2	+ 2
After	3 u + 40	3 u + 40	4 u + 29

Amount that Pierre had in the end = 3 u + 40 

Amount that Mark had in the end = 4 u + 29

Amount that David had at first 
= 3 u + 40 + 42 + 27
= 3 u + 109

Amount that Pierre and Mark had in the end is the same.

3 u + 40 = 4 u + 29
4 u - 3 u = 40 - 29

1 u = 11

Amount that David and Pierre had in the end is the same.

Amount that David had in the end
= 3 u + 40
= 3 x 11 + 40
= 33 + 40
= $73

Amount that David had at first
= 73 + 42 + 27
= $142

Difference in the amounts between David and Pierre at first
= 142 - 33
= $109

Answer(s): $109