Question #N252
A store sells bags of candy. Each bag contains either 10 or 15 pieces of candy. On Monday, the store sold 100 bags of candy containing a total of 1,300 pieces of candy. How many bags of candy containing 15 pieces of candy were sold that day?
A. 20
B. 40
C. 60
D. 80
Correct Answer is: C
Let x be the number of bags containing 10 pieces of candy and y be the number of bags containing 15 pieces of candy. We are given that x + y = 100 and 10x + 15y = 1300. Multiplying the first equation by 10 gives 10x + 10y = 1000. Subtracting this equation from the second equation yields 5y = 300. Dividing both sides of this equation by 5 yields y = 60. So 60 bags containing 15 pieces of candy were sold.