A hotel has 260 rooms. Some are singles, and some are doubles. Thesingles cost 35 and the doubles cost 60. Because of a math teachers' convention, all of the hotel rooms are occupied. The sales for this night are
14,000. How many double rooms does the hotel have?
+592 s + d = 260
35s + 60d = 14000
35s = 14000 - 60d
s = 400 - 12d/7
s + d = 260
(400 - 12d/7) + d = 260
-12d/7 + d = -140
-12d + 7d = -980
-5d = -980
d = 196
s + d = 260
s + (196) = 260
s = 64
The hotel has 196 double rooms :)
