Question

A theater has 37 seats in the first row, 39 seats in the second row, 41 seats in the third row, and so on. How many seats are there in row 18?

Answer 1

Given:

37 seats in the first row, 39 seats in the second row, 41 seats in the third row, and so on.

Given values can be written as a AP sequence.

37,39,41,...

$a=37\text{ , d=39-37=2}$$t_n=a+(n-1)d$

When n=18

$\begin{gathered} t_{18}=37+(18-1)(2) \\ t_{18}=37+34 \\ t_{18}=71 \end{gathered}$

No of seats in row 18 are 71.