Bob and Bill were washing cars. Bob can wash a car in 6 minutes. Bill can wash a car in 8 minutes. How long will it take if Bob and Bill wash a car together?
It doesn't have to be this exact problem but how do you solve these type in general. Show steps please, and explain reasoning behind equations.
2007-09-26 15:21:16 · 7 answers · asked by Tesline T 2 in Science & Mathematics ➔ Mathematics
thanks all of you!
2007-09-28 13:25:01 · update #1
Bob can wash the entire car in 6 minutes. That means, in one minute, he can wash 1/6 of the car.
Bill can wash the entire car in 8 minutes. That means, in one minute, he can wash 1/8 of the car.
If both of them washed the car, they can wash 1/6 + 1/8 of the car every minute.
1/6 + 1/8 = 4/24 + 3/24 = 7/24
Since there is only ONE car, if they can wash 7/24th of the car in one minute, it will take 1 / (7/24) minutes to wash the entire car.
1/(7/24) = 24/7 = approx. 3.43 minutes.
2007-09-26 15:27:20 · answer #1 · answered by tkquestion 7 · 0⤊ 0⤋
ok. In one minute, Bob can wash 1/6 of a car, and Bill can wash 1/8. So if they are together, add both together and that is how much of a car they wash in 1 minute
3/24+4/24=7/24
They can wash 7/ 24 of a car in one minute
2 min=14/24
3 21/24
4 28/24
in 4 minutes, they clean 1 and 1/6 of a car. So its less than four but more than 3.
The rest you must figure out on your own young grasshopper.
(You didnt think your homework could be done this easy, did ya? Otherwise you wouldn't learn anything)
2007-09-26 15:31:07 · answer #2 · answered by monkeyinaplane 2 · 0⤊ 0⤋
So, what is Bob's rate? How much of a car can he wash in one minute? Well, if he can wash one car in six minutes, then he can wash 1/6 of a car in one minute, right? Similarly, Bill can wash 1/8 of a car in one minute. So just add their two rates together to find out how much of a car they can do together, in one minute, as they work side by side on the same car: 1/6 + 1/8 = 7/24 of a car in one minute. That's their combined RATE. (Note: that's a little bit less than 1/3 of a car in one minute). From this point, the way you want to think of it depends on your favorite way of dealing with fractions. You now have their rate. It's 7/24 cars per minute. You can either just take its reciprocal and say: 24/7 minutes for one car, and you're done.
answer 24/7 or its reciprocal 7/24
2007-09-26 15:35:34 · answer #3 · answered by Cody M 3 · 0⤊ 0⤋
I think that this is a problem of averages....so i would add the time together 6 plus 8 and then divide by 2. On average it would take them 7 minutes to wash the car together.
Hope I helped
2007-09-26 15:25:16 · answer #4 · answered by Anonymous · 0⤊ 0⤋
hi pal this an trouble-free question in reaction to linear equations you need to use transposition approach in this technique whilst a term is transfered from one area to different its sign turns into opposite answer: x+4-7x=22 =4-7x=22-x (right here x comes from the left area its sign variations) =4=22-x+7x(right here 7x comes from the left area its sign variations) =4-22=6x(comparable) =-18=6x x=-18/6 =-3 Bye Bye!!!!!!!!!!!!!!!!!!!!!!
2016-12-28 04:50:29 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Check yahoo answers before you post the same homework problem someone else already did.
2007-09-26 15:25:07 · answer #6 · answered by lhvinny 7 · 0⤊ 0⤋
3.5 MNT ( 6+ 8 )/4 = 3.5 M
AVERAGE / 2
2007-09-26 15:25:12 · answer #7 · answered by Anonymous · 0⤊ 0⤋