The Grass Doctor

Please assist with word problem HELP?

A new lawn mover can cut the grass on the fairways of a golf course in half the time it takes another mower to do the same job. If it takes 7 hours to finish the job when both mowers are working together, how long would it take each mover working alone? show work

Public Comments

1. idk
2. 21housr for the old mower 10.5 hours for the new mower
3. first worker in x hours second in y hours x=2y xy/x+y =7 --->2y^2/3y =7 ---->y=10.5---->x=21
4. Hours the faster mower (x) can finish: 1/x + 1/2x = 1/7 (2 + 1)/2x = 1/7 3 = 2x/7 2x = 21 x = 10 1/2 Hours the slower mower can finish: = 2(21/2) = 21 Answer: faster mower, 10 1/2 hrs; slower mower, 21 hrs Checking (1 job after 7 hrs working together): = 7(1/[10 1/2] + 1/21) = 7(1/[21/2] + 1/21) = 7(2/21 + 1/21) = 7(3/21) = 21/21 or 1