OG242

zhoucuiye

242. The number of seats in the fi rst row of an auditorium
is 18 and the number of seats in each row thereafter
is 2 more than in the previous row. What is the total
number of seats in the rows of the auditorium?
(1) The number of rows of seats in the auditorium
is 27.
(2) The number of seats in the last row is 70.

Yelang

应该是D，用等差数列能求出

飞天小猪Piggy

对的，应该选D，都可以求出来。