Question

The number of seats in each row of an auditorium increases by 2 from one row to the next. if there are 48 seats in the first row, how many seats are there in the 60th row?

Answer 1

Let's see if we can find a pattern:

Row number 1 has $48 = 48 + 2\cdot 0$ seats

Row number 2 has $50 = 48 + 2\cdot 1$ seats

Row number 3 has $52 = 48 + 2\cdot 2$ seats

Row number 4 has $54 = 48 + 2\cdot 3$ seats

Can you see the pattern? After $n$ rows, we have added $2(n-1)$ seats.

So, the 60th row will have

$48 + 2\cdot 59 = 48 + 118 = 166$