The opera house had 2030 seats. There were 25% fewer $45-seats than $15-seats. 50% of the $15-seats and some $45-seats were sold. A total of $28950 was collected. How many seats were unsold?

	$45	$15	Total
Number	3 u	4 u	7 u

100% - 25% = 75%
⁷⁵₁₀₀ = ³₄

Total number of seats
= 3 u + 4 u
= 7 u

7 u = 2030

1 u = 2030 ÷ 7 = 290

Total number of $15-seat tickets
= 4 u
= 4 x 290
= 1160

Number of $15-seat tickets sold
= 50% x 1160
= ⁵⁰₁₀₀ x 1160
= 580

Amount collected from $15-seat tickets sold
= 580 x 15
= $8700

Amount collected from $45-seat tickets sold
= 28950 - 8700
= $20250

Number of $45-seat tickets sold
= 20250 ÷ 45
= 450

Number of tickets sold
= 580 + 450
= 1030

Number of tickets left unsold
= 2030 - 1030
= 1000

Answer(s): 1000