Question

HEELP! NEED WORK!

A stadium with 75 rows has 10 seats the 1st row, 15 in the 2nd, 20 in the 3rd and so on.
How many seats are in the 75th row? How many seats are in the stadium?

Answer 1

380

Explanation:

This is an airthmatic sequence

we can use the following equation to find the nth term

a₁+(n-1)d

where the common difference (d) is 5

and the first term (a₁) is 10

and n is 75

we have

10+(75-1)*5

10+370

380