Question

In a theater, each row has a fixed number of seats compared to the one in front of it. The 3rd row has 38 seats, and the 7th row has 62 seats. If there are a total of 35 rows in the theater, how many seats are there in total?

• A. 4804
• B. 4480
• C. 4840
• D. 4088

Answer 1

Answer:

C. 4840

This is an arithmetic progression third term= a + (n-1)d a + 2d = 38 .....(1) seventh term= a + 6d = 62. .....(2) (2) - (1) = 4d = 24 d = 6 (1)= a+ 12 = 38 a= 38 - 12 = 26 Total seats= n/2(2a+(n-1)d 35/2(2×26 + 34×6) = 4840