Question

Help with this world problem !!!!
Cole and Mary can clean a room together in 5 hours. Working alone, Cole can clean the room in 1 hour less time than Mary can. How long does it take Mary to clean the room alone ?????!

Answer 1

5cole+5mary=x
ycole =x ---- cole takes y hours to clean the room
(y+1)mary=x ---- mary takes y+1 hours to clean the room
Re-arrange the latter two:
cole=x/y
mary=x/(y+1)
Substitute into the original:
(5x/y)+(5x/y-1)=x
divide by 5x->
1/y+(1/(y-1))=1/5
solve for y, y =10.52
cole takes 10.52 hours
mary takes 11.52 hours
I'm not sure, but that's my best go. Good question.

Answer 2

mistake on line 8, it's 5x/(y+1). the answer is 10.52 for mary, 9.52 for cole.