On day one, a store sold 86 cups. On each of the next d days, the company sold 50 cups. If the average daily sales of cups over this time period (including day one) is 53 cups, what is the value of d?	Pick one:
A) 9
B) 10
C) 11
D) 12
E) 13
86 + 50d = 53(d+1).   3d = 33.   d = 11.   The answer is 11.
<result>C</result>
On day one, a store sold 86 cups. On each of the next d days, the company sold 50 cups. If the average daily sales of cups over this time period (including day one) is 53 cups, what is the value of d?