Grazes
A worker can build a fence in 8 hours, With the help of an assistant, the fence can be built in 5 hours. How long should it take the assistant, working alone, to build the fence?
Delete
Share
This Question is Closed
Lily_980
Best Response
You've already chosen the best response.
0
Wouldn't it be the same amount of hours?
JamesWolf
Best Response
You've already chosen the best response.
0
What was wrong with my previous answer?
JamesWolf
Best Response
You've already chosen the best response.
0
9 hours.
Grazes
Best Response
You've already chosen the best response.
0
Not necessarily. And could you please show some work?
JamesWolf
Best Response
You've already chosen the best response.
0
well lets say the assistant worked at the same rate as the worker. then it would take half the time, 4 hours right.
Grazes
Best Response
You've already chosen the best response.
0
Oh. Nevermind. The answer is 40/3 hours.
JamesWolf
Best Response
You've already chosen the best response.
0
oh :(
JamesWolf
Best Response
You've already chosen the best response.
0
13 hours? how?
Grazes
Best Response
You've already chosen the best response.
0
Worker=W
Assistant=A
1/A+1/W=1/5
1/A+1/8=1/5
8+A/8A=1/5
5*(8+A)=8A
40+5A=8A
3A=40
A=40/3 hours
JamesWolf
Best Response
You've already chosen the best response.
0
are you sure?
JamesWolf
Best Response
You've already chosen the best response.
0
why 1/A ?
Grazes
Best Response
You've already chosen the best response.
0
It's the work rate.
Grazes
Best Response
You've already chosen the best response.
0
Algebra.
JamesWolf
Best Response
You've already chosen the best response.
0
why is the rate 1/A ?
JamesWolf
Best Response
You've already chosen the best response.
0
sorry, i dont get it
Grazes
Best Response
You've already chosen the best response.
0
So it takes you 6 minutes to shower, right?
Grazes
Best Response
You've already chosen the best response.
0
You've showered for 2 minutes already. Doesn't that mean that you showered for 2/6 of the regular shower time or 1/3?
JamesWolf
Best Response
You've already chosen the best response.
0
That makes sense.