The auditorium had 1472 seats. There were 40% fewer $30-seats than $10-seats. 80% of the $10-seats and some $30-seats were sold. A total of $19150 was collected. How many seats were unsold?

	$30	$10	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 = 1472

1 u = 1472 ÷ 8 = 184

Total number of $10-seat tickets
= 5 u
= 5 x 184
= 920

Number of $10-seat tickets sold
= 80% x 920
= ⁸⁰₁₀₀ x 920
= 736

Amount collected from $10-seat tickets sold
= 736 x 10
= $7360

Amount collected from $30-seat tickets sold
= 19150 - 7360
= $11790

Number of $30-seat tickets sold
= 11790 ÷ 30
= 393

Number of tickets sold
= 736 + 393
= 1129

Number of tickets left unsold
= 1472 - 1129
= 343

Answer(s): 343