Posted by **john** on Monday, July 23, 2012 at 12:13am.

john takes 3hours longer than andrew to peel 400 pounds of apples. if together they can peel 400pounds of apples in 8hours then how long would it take john if he is working alone.

- math -
**Reiny**, Monday, July 23, 2012 at 8:34am
Andrew's rate = 400/x

Johns rate = 400/(x+3)

combined rate = (400(x+3) + 400x)/(x(x+3)

= 400(2x+2)/(x(x+2))

400 / [400(2x+3)/(x(x+3) ] = 8

1/[2x+3)/(x(x+2)) ] = 8

x(x+3)/(2x+3) = 8

x^2+3x = 16x + 24

x^2 - 13x - 24 = 0

x = (13 ±√265)/2

x = 14.64 hrs , ignoring the negative answer

check:

combined rate = 1/14.64 + 1/17.64 = .125

time at comined time = 1/.125 = 8 , Yeahh!

Andrew alone can do it in 14.65 hrs

John alone can do it in 17.65 hrs

## Answer this Question

## Related Questions

- Math - John takes 2 hours longer than Andrew to peel 400 pounds of apples. If ...
- algebra - John takes 3 hours longer than Andrew to peel 400 pounds of apples. ...
- math - john and mary are working on a job together. if john does it alone, it ...
- math - Q1.The zoo uses 10 pounds of apples each day. How many pounds of apples ...
- 5th grade math - John picked 30 bags of apples on monday and sold them at his ...
- business - Suppose the price of apples rises from $3.50 a pound to $4.00 and ...
- economics - Suppose the price of apples rises from $3.50 a pound to $4.00 and ...
- math - Audrey bought 7 pounds of diced apples and shared them equally among 4 ...
- Math - Audrey bought 7 pounds of diced apples and shared them equally among 4 ...
- math - A michigan orchard made 11,491lb of taffy apples with approximately 1lb ...

More Related Questions