The theatre had 1953 seats. There were 20% fewer $30-seats than $20-seats. 80% of the $20-seats and some $30-seats were sold. A total of $26630 was collected. How many seats were unsold?

	$30	$20	Total
Number	4 u	5 u	9 u

100% - 20% = 80%
⁸⁰₁₀₀ = ⁴₅

Total number of seats
= 4 u + 5 u
= 9 u

9 u = 1953

1 u = 1953 ÷ 9 = 217

Total number of $20-seat tickets
= 5 u
= 5 x 217
= 1085

Number of $20-seat tickets sold
= 80% x 1085
= ⁸⁰₁₀₀ x 1085
= 868

Amount collected from $20-seat tickets sold
= 868 x 20
= $17360

Amount collected from $30-seat tickets sold
= 26630 - 17360
= $9270

Number of $30-seat tickets sold
= 9270 ÷ 30
= 309

Number of tickets sold
= 868 + 309
= 1177

Number of tickets left unsold
= 1953 - 1177
= 776

Answer(s): 776