Determine the seating capacity of an auditorium with 35 rows of seats if there are 20 seats in the first row, 23 seats in the second row, 26 seats in the third row, 29 seats in the forth row, and so on.

  2485

Step-by-step explanation:

The number of seats in row n is given by the explicit formula for an arithmetic sequence:

  an = a1 +d(n -1)

  an = 20 +3(n -1)

The middle row is row 18, so has ...

  a18 = 20 + 3(18 -1) = 71 . . . . seats

The total number of seats is the product of the number of rows and the number of seats in the middle row:

  capacity = (71)(35) = 2485

The seating capacity is 2485.

The measure of the angle is 15 degree.

Step-by-step explanation:

The measure of the supplement of an angle is 60 less than three times the measure of the complement of the angle.

Supplementary angles are those that add up to 180, and complementary angles add up to 90.

Let represent the angle.

is the supplementary angle and is the complementary angle.

is the complementary

is the supplementary angle