The opera house had 1888 seats. There were 40% fewer $50-seats than $15-seats. 80% of the $15-seats and some $50-seats were sold. A total of $36560 was collected. How many seats were unsold?

	$50	$15	Total
Number	3 u	5 u	8 u

100% - 40% = 60%
⁶⁰₁₀₀ = ³₅

Total number of seats
= 3 u + 5 u
= 8 u

8 u = 1888

1 u = 1888 ÷ 8 = 236

Total number of $15-seat tickets
= 5 u
= 5 x 236
= 1180

Number of $15-seat tickets sold
= 80% x 1180
= ⁸⁰₁₀₀ x 1180
= 944

Amount collected from $15-seat tickets sold
= 944 x 15
= $14160

Amount collected from $50-seat tickets sold
= 36560 - 14160
= $22400

Number of $50-seat tickets sold
= 22400 ÷ 50
= 448

Number of tickets sold
= 944 + 448
= 1392

Number of tickets left unsold
= 1888 - 1392
= 496

Answer(s): 496