MATHEMATICS · Single correct · A Level · Mathematics · Sequences and series · Sequences and series
Problem
An auditorium has 20 rows of seats. The first row has 30 seats and the last row has 69 seats, with the number of seats increasing uniformly from one row to the next. What is the total number of seats in the auditorium?
(a) 1011
(b) 990
(c) 1000
(d) 941