Wednesday

July 30, 2014

July 30, 2014

Posted by **Sara** on Thursday, May 17, 2012 at 6:24pm.

2) Matt and Sara mow lawns together. When Matt mows the lawn for Mr. Smith it takes 100 minutes. When matt and Sara work together to mow the lawn for Smith they get the job done in 40 minutes. How long will it take Sara to mow Smith's lawn by herself?

- Math -
**Reiny**, Thursday, May 17, 2012 at 6:45pmspeed of private plane --- x mph

speed of jet -----> 3x mph

time for 1st leg of trip = 1350/x

time for 2nd leg of trip = 600/(3x) = 200/x

so 1350/x + 200/x = 6

1550/x=6

6x = 1550

x = 258.333..

private plane went 258.33 mph, jet went 775 mph

- Math -
**Reiny**, Thursday, May 17, 2012 at 6:50pmMatt's rate = lawn/100

Sara's rate = lawn/x , where x is Sara's time if she works alone

combined rate = lawn/100 + lawn/x

= (xlawn + 100lawn)/(100x)

= lawn*(x+100)/(100x)

then lawn*(x+100)/(100x) = lawn/40

(x+100)/(100x) = 1/40

cross-multiply

100x = 40x + 4000

60x = 4000

x = 66.666. or 66 2/3 minutes

**Related Questions**

algebra - a two part canoe trip,the first part of the trip the canoist traveled...

Math - Cari Bean was on her way to the islands in her yachet. Because of the ...

math - last year bill traveled 6,589 miles on business. Donna traveled 4,309 ...

math - jenny had driven for 2h at a constant speed when road forced to reduce ...

Math - Ms.abbot went on a road trip. The trip was 792 miles and the average ...

Statistics - According to the U.S. Federal Highway Administration, the mean ...

4th grade math - Aaron's family is driving 80 miles to the mountains. They have ...

math-fractions - last season a little league baseball team traveled a total of ...

math - a heavy freight train made a trip of 360 miles, running part of the ...

Algebra Help - A motorist was to travel from town A to town B, a distance of 80 ...