Question

A contractor estimated that one of his two brick layers would take 9 hours to build a certain wall and the other 10 hours. However, he knew from experience that when they worked together, 10 fewer bricks were laid per hour. Since he was in a hurry, he put both men on the job and found it took exactly 5 hours to build the wall. How many bricks did the wall contain?

Answer 1

Answer:

900

Step-by-step explanation:

Assume x brick

X*(1／9+1/10）一 10=X/5

X(19/90-1/5)=10

X*(1/90)=10

X=900