13. Photography world has a portrait special. A three-pose portrait package has a sitting fee of $35,
and a six-pose package has a sitting fee of $60. On a
Saturday, $690 was collected in sitting fees. Which
equation can be used to represent x, the number of
three-pose portrait packages, and y, the number of
six-pose portrait packages?
A. 360x + 105y = 690
B. 35x + 60y = 690
C. 60x + 35y = 690
D. 105x + 360y = -690