<PRE><B>Question 1206889</B>
&lt;br&gt;
The 10 rows have numbers of logs that form an arithmetic sequence.&lt;br&gt;
With 10 rows and 24 on the bottom row and 15 on the top row, the common difference in the arithmetic sequence is 1.&lt;br&gt;
But we don&#39;t need to know that common difference to answer the question.&lt;br&gt;
In any set of numbers, the sum of the numbers is&lt;br&gt;
(number of numbers) * (average of the numbers)&lt;br&gt;
In an arithmetic sequence, the average of all the numbers is the average of the first and last numbers.&lt;br&gt;
In this problem we are given the number of rows of logs and the numbers of logs in the first and last rows, so we have all we need to find the total number of logs.&lt;br&gt;
(number of numbers) * (average of the numbers) = {{{(10)((24+15)/2)=10(39/2)=5*39=195}}}&lt;br&gt;
ANSWER: 195&lt;br&gt;
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