Several logs are stored in a pile with 22 logs on the bottom layer, 21 on the second layer, 20 on the third layer, and so on. If the top layer has one log, how many logs are in the pile?
A)252
B)253
C)242
D)231
E)none of the above

Question

Quizplus · Accepted Answer

We can use the sum of an arithmetic sequence formula to find the total number of logs. The common difference between each layer is 1 (since each layer has one less log than the layer below it), and there are 22 layers (since the top layer has one log). Thus, the total number of logs is:

(22/2)(22 + 1) = 11(23) = 253

Therefore, the answer is (B) 253.

Several Logs Are Stored in a Pile with 22 Logs