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Question

Two bricklayers, Alan and David, each place 30 bricks per hour. Alan worked three times as many hours as David, and the two of them placed a total of 600 bricks. How many bricks did David lay?

Accepted Answer

Let t equal the amount of time David worked. Therefore, Alan worked 3t hours. They placed a total of 30 t +30 3t=600 bricks. Solving for t, we find that t=5 hours. Therefore, David placed 30 5 = 150 bricks.