Use the formula for the sum of the first n terms of an arithmetic sequence to find the indicated sum.
-As part of her retirement savings plan, Patricia deposited $250 in a bank account during her first year in the workforce. During each subsequent year, she deposited $35 more than the previous year. Find how much she deposited during her twentieth year in the workforce. Find the total amount deposited in the twenty years.
A) $915; $11,650
B) $950; $12,000
C) $915; $23,300
D) $950; $24,000

Question

Quizplus · Accepted Answer

The 20th term of the arithmetic sequence is 250 + (20 - 1)35 = 915. The sum of the first 20 terms is (20/2)(250 + 915) = 11,650.

Use the Formula for the Sum of the First N