This makes no sense.
If the 15th row has 50 seats,
the 14th row has 40 seats
the 13th row has 30 seats
...
the 10th row has 0 seats
the 9th row has -10 seats ????????
check your question
If the 15th row has 50 seats,
the 14th row has 40 seats
the 13th row has 30 seats
...
the 10th row has 0 seats
the 9th row has -10 seats ????????
check your question
they match your problem once you fixed it.
a = 15
d=10
then
S50 = 50/2 (2*15 + 49*10) = ____ seats total
Given:
Number of rows = 15
Number of seats in the last row, which is the back row = 50
Since each row has 10 seats more than the previous row, we can set up an equation to calculate the number of seats in each row:
Number of seats in a row = Number of seats in the back row + (Number of rows - 1) * 10
Number of seats in each row = 50 + (15 - 1) * 10
= 50 + 14 * 10
= 50 + 140
= 190
Now, to find the total number of seats, we need to multiply the number of seats in each row by the number of rows:
Total number of seats = Number of rows * Number of seats in each row
= 15 * 190
= 2850
Therefore, the total number of seats in the auditorium is 2850.