Question 1039333
Rina will hold her piano recital at the music hall of her school. The music hall has 12 rows of seats, in which the first row has 15 seats. Each succeeding row has 3 more seats than the one in front of it. What is the maximum number of people who can be seated in the music hall?
<pre>This scenario represents an arithmetic progression (AP), and the formula for the sum of an AP is used: {{{S[n] = (n/2)(2a[1] + (n - 1)d)}}}, with:
n, or number in series: 12; {{{a[1]}}}, or 1st term: 15, and d, or common difference = 3
{{{S[12] = (12/2)(2(15) + (12 - 1)3)}}}
{{{S[12] = 6(30 + 11(3))}}}
{{{S[12] = 6(30 + 33)}}}
{{{S[12] = 6(63)}}}
{{{highlight_green(matrix(1,11, S[12], or, number, of, people, who, can, be, seated, "=", 378))}}}