As per the question each row must have 6 seats more than the row before it. And there are 11 seats in the first row.
So, the first row has 11 seats
2nd row has 11+6 seats
3rd row has 11+2*6=11+12=23
4th row has 11+3*6=11+18=29
and so on...
We know that the difference between any two consecutive integers in an arithmetic progression (AP) sequence of numbers is always the same amount. Arithmetic progression can be calculated as
aₙ = a₁ + (n - 1)d,
where aₙ is the nth and a₁ is the first term of this progression respectively and d is the common difference between terms.
So, we can observe the trend and develop the equation for the problem.
There are 11+(n-1)*6 seats in the n-th row.
So, there is 11+(18-1)*6=11+17*6=113 seats in the 18th row.
Therefore, there are 113 seats in the 18th row.
Know more about arithmetic progression here -
brainly.com/question/27841335
#SPJ10
