At a concession stand, a pickle and two bags of chips cost a total of $3.25. Three pickles and four bags of chips cost a total of $7.25. To determine the cost of one pickle, Kevin is writing a system of equations. His first equation is shown: x+2y=3.25 Which of the following could be the second equation in his system of equations?
a) 4x+3y=7.25

b) 3x-4y=7.25

c) 3x+4y=7.25

d) (3+4)x=7.25