Solve the problem.
-A person puts $20 into a bank account on January 1, $25 on February 1, $30 on March 1, and so forth. How much has the person put into the bank account by December 30?
A)$450
B)$600
C)$1140
D)$570

Question

Quizplus · Accepted Answer

This is an arithmetic sequence where the first term, a = $20, the common difference, d = $5, and the number of terms, n = 12 (for the 12 months). The sum of an arithmetic series is given by S = n/2[2a + (n-1)d]. Substituting the given values, S = 12/2[2(20) + (12-1)5] = 6[40 + 55] = 6 * 95 = $570.

Solve the Problem. -A Person Puts $20 into a Bank Account on January