The symphony sells two kinds of tickets: orchestra, for $30, and upper tiers, for $12. On a certain night, the symphony sells 90 tickets and gets $1836 in revenue from the sales. How many orchestra tickets did they sell?  Select
A) 38	B) 42	C) 46	D) 50	E) 54
Let x be the number of orchestra tickets.   Then 90-x is the number of upper tier tickets.   30x + 12(90-x) = 1836   18x = 1836-1080   x = 42   The answer is 42.
<result>B</result>
The symphony sells two kinds of tickets: orchestra, for $30, and upper tiers, for $12. On a certain night, the symphony sells 90 tickets and gets $1836 in revenue from the sales. How many orchestra tickets did they sell?