SOLUTION: Log area stacked in a pile. The bottom row has 21 logs and the top row has 15 logs. Each row has less log that the row below it. How many logs are in the pile.
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Question 775623: Log area stacked in a pile. The bottom row has 21 logs and the top row has 15 logs. Each row has less log that the row below it. How many logs are in the pile. Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website! Log area stacked in a pile. The bottom row has 21 logs and the top row has 15 logs. Each row has less log that the row below it. How many logs are in the pile.
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Add 15, 16, 17...21
Group them as 3 pairs: 15+21, 16+20 & 17+19
Each pair is 36
36*3 + 18 = 126 logs
