Saturday

September 20, 2014

September 20, 2014

Posted by **Cerra** on Saturday, November 27, 2010 at 5:41pm.

- math -
**Reiny**, Saturday, November 27, 2010 at 7:02pmrate of faster person = 1/x

rate of slower person = 1/(x+1)

combined rate = 1/x + 1/(x+1) = (2x+1)/(x(x+1))

so time with combined rate = 1/[(2x+1)/(x(x+1))

= x(x+1)/(2x+1)

so x(x+1)/(2x+1) = 4

x^2 + x = 8x + 4

x^2 - 7x -4 = 0

x = (7 ± √ 65)/2

= 7.53 or a negatiave

So one takes 7.53 hours, the other 8.53 hours

**Answer this Question**

**Related Questions**

college intermediate algebra - Working together, two people can mow the lawn in ...

Math - Mike can mow a lawn in 3 hours. Paul can mow the same lawn in 2 hours. ...

math - A father can do a job as fast as two sons working together. If one sone ...

smith - tom can mow a lawn in 4 hours. perry can mow the same lawn in 5 hours. ...

algebra - Kim can mow the greens at golf course twice as fast as I can. Working ...

algebra - Kim can mow the greens at golf course twice as fast as I can. Working ...

MATH - Jack usually mows his lawn in 3 hours. Marilyn can mow the same yard in 5...

Algebra II - Jack usually mows his lawn in 6 hours. Marilyn can mow the same ...

Math!! - You work in retail. In the past you inventoried and shelved the weekly ...

Algebra 2 - It takes you 3 hours to mow a lawn & it takes your sister 2 hours to...