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Question 1168382: Working alone, it takes Asanji EIGHT hours to dig a 10 ft by 10 ft hole. Brenda can dig the same hole in NINE hours. How long would it take them if they worked together
Found 3 solutions by josgarithmetic, ikleyn, Boreal:
Answer by josgarithmetic(39617)   (Show Source):
You can put this solution on YOUR website! Very frequent exercise type for two workers with different speeds each, working at the same time
 
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VERY FREQUENT CONSTANT RATES TYPE EXERCISE FOR TWO WORKERS AT DIFFERENT RATES WORKING TOGETHER - THEIR RATES ARE ADDITIVE. FIND THEIR COMBINED RATE!
Answer by ikleyn(52787)  (Show Source):
You can put this solution on YOUR website! .
Notice that the dimensions of the hole are an excessive and unnecessary info in this problem.
Also notice that the problem gives only two dimensions of the hole, while we live in 3D space.
Answer by Boreal(15235)  (Show Source):
You can put this solution on YOUR website! in 1 hour, A digs (1/8) of hole and in x hours, he digs (x/8) of a hole
B digs (x/9) of a hole in x hours by the same reasoning,.Together, they dig 1 hole.
So (x/8)+(x/9)=1
9x+8x=72
17x=72
x=72/17=4.24 hours
in that time, A digs (4.24/8) and B digs (4.24/9) of the hole, 53/47.
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