OpenStudy (anonymous):

a theatre has 30 rows of seats. there are 16 seats in the first row and each additional row has 2 more seats than the previous row. Seats are allocated randomly to all theatre patrons. Calculate the probability that a randomly chosen patron will be seated in the last row of the theatre

6 years ago
hero (hero):

gabby, what course are you taking?

6 years ago
OpenStudy (campbell_st):

there are several parts to this question firstly the seating forms an arithmetic sequence you have a = 16, d = 2 and n = 30 you will need to find the sum of the seats in the theatre use $s _{n} = \frac{n}{2}[2a + (n -1)d]$ then you will need to find the number of seats in the 30th row $T _{n} = a +(n -1) d$ this information will be needed for the probability question P( last row seat) = (number of seats in the last row)/(total number of seats) hope this helps

6 years ago
OpenStudy (anonymous):

I'm taking pre calc sorry for the late response

6 years ago
OpenStudy (anonymous):

Yeah it did help thanks ! (:

6 years ago