Pamela has some mochi balls and chocolate bars. If she packs a mochi ball and a chocolate bar in each bag, there will be 13 chocolate bars left. If she packs 3 mochi balls and 4 chocolate bars in each bag, there will be 16 mochi balls left. How many mochi balls and chocolate bars does she have in all?

	Case 1		Case 2
	Mochi Balls	Chocolate Bars	Mochi Balls	Chocolate Bars
Before	1 u	1 u + 13	3 p + 16	4 p
Change	- 1 u	- 1 u	- 3 p	- 4 p
After	0	13	16	0

The number of mochi balls at first is the same for Case 1 and 2.
The number of chocolate bars at first is also the same for Case 1 and 2.

1 u = 3 p + 16 --- (1)

1 u + 13 = 4 p
1 u = 4 p - 13 --- (2)

(2) = (1)
4 p - 13 = 3 p + 16
4 p - 3 p = 16 + 13

1 p = 29

Total number of mochi balls and chocolate bars
= (3 p + 16) + 4 p
= 7 p + 16
= 7 x 29 + 16
= 203 + 16
= 219

Answer(s): 219