1972 AHSME Problems/Problem 15
A contractor estimated that one of his two bricklayers would take hours to build a certain wall and the other hours. However, he knew from experience that when they worked together, their combined output fell by bricks per hour. Being in a hurry, he put both men on the job and found that it took exactly 5 hours to build the wall. The number of bricks in the wall was
Every hour, the contractors lay and bricks, assuming a total of bricks in the wall. Together, bricks are laid per hour: There are a total of bricks, and the answer is .
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