Logs are stacked so that there are 17 logs in the bottom row, 16 logs in the second row from the bottom, and so on, decreasing by 1 log each row. How many logs are there in the first five rows from the bottom?
A)117 logs
B)108 logs
C)75 logs
D)87 logs
E)125 logs

Question

Quizplus · Accepted Answer

The number of logs in the first five rows is the sum of the first five terms of the sequence: 17, 16, 15, 14, 13. The sum is 17 + 16 + 15 + 14 + 13 = 75 logs.

Logs Are Stacked So That There Are 17 Logs in the Bottom