question on algebra 2 test today

[MassOccur 10+ year member]

Don't know if this is answered yet, but oh well.

1 = done in 8 hours...

Other = done in 12 hours.

If they could both do it in 8 hours, it would be cut to 4 hours because it would be twice as fast, so 4 hours is out of the question. 12 hours is 4 hours more (1/3rd), which leaves 2/3rds or .66666, etc. 8 hours x .66666666 = 5.3333 = 5 hours and 20 minutes or so. I may not be right, but that's my guess.

 

[mattmcss 10+ year member]

Its been answered, look on page two.

 

[MassOccur 10+ year member]

Its been answered, look on page two.

I saw. Just didn't feel like editing my post. For not being the best at math, my guess was a lot closer than some others.

*Shrugs* I still stand by my wrong answer.

 

[dan7532 10+ year member]

 

[MassOccur 10+ year member]

I lol'd.

 

[sumone 10+ year member]

1 + 1 = 2

2 + 2 = 4

4 + 4 = 8

8 + 8 = 10

10 + 10 = 20

20 + 20 = 40

40 + 40 = 80

....

there you go.

ndnbolla had it...

1       1
---[i]X[/i] + -----[i]X[/i] =  1
8       12

One person does an eighth of a room in an hour, the other a twelfth of a room in an hour, this represents the rate or speed (units are rooms/hour). (rooms/hour) * hour = rooms (which is 1).

 

[budahbuddy803 10+ year member]

x2, same answer I got.
think about it like this too..

person A paints at a rate of 1 room per 8 hours

so 1room /8hours

Person B is 1 room per 12 hours, so 1room/12hours

1room/8 hours + 1room/12hrs = 1 room / x hours

1/8 + 1/12 = 1/x

Solve for x.

well that is the answer. 8/x + 12/x = 1 and it comes out to 4.8 hours