Simple one...10 points up for grab!!!Thirty men take 20 days to complete a?

Question

Thirty men take 20 days to complete a job working 9 hours a day.How many hour a day should 40 men work to complete the job?

Answer 1

4 hours and 30 minutes a day.

Answer 2

One man to complete a job:
30 x 20 x 9
= 600 x 9
= 5400 hours

40 men to complete a job:
5400 ÷ 40 ÷ 3
= 135 ÷ 3
= 4.5 hours per day

Answer 3

Finding a work hour for one;we get
manhour=30(mens)*20(days)*9(hours)
=5400 hours per men
Working hours of 40 mens=5400/40
=135 hours on the whole
:depending on 9 hours a day;135/9
=15 days
The answer is 15 days.(135 hours)

Answer 4

The total man-hours to do the job is (30)(20)(9) = 5400 man-hours.

Assuming 40 men working 20 days gives the following equation

(40)(20)(x) = 5400 man-hours

Solving for x gives 6.75 hours/day.

Answer 5

If we assume that they work just as efficiently as the 30 men, then we can solve this. Since 40 * 3/4 = 30, the 40 men only need to work for 3/4 of the time to finish.

So, if they want to finish in 20 days, they only need to work 9*3/4 = 27/4 = 6 3/4 = 6.75 hours = 6 hours 45 minutes per day.

However, if they continue to work 9 hour days, then they only need to work for 20*3/4 = 60/4 = 15 days to finish.

To check, we can multiply the number of men working times the hours worked per day times the number of days worked. This gives us the number of "man-hours" that it takes to complete the project. In this case, it takes 30*20*9 = 5400 man-hours. You can check that we still have 5400 man-hours in the solution.

I hope this helps!

Answer 6

30 men * 9 hours a day * 20 days = 5400 man hours.
5400 man hours / 40 men / 20 days = 6.75 hours a day.

Answer 7

30men x 9 hr = 40 men x t
t = (30 men x 9 hr)/40 men
t = 6.75 hr ANS

teddy boy

Answer 8

Assumption: The style of days is the comparable for the two the 30 adult adult males AND the 40 adult adult males (20 days). the version is the hours in line with day (9 as against ?). yet another Assumption: greater adult adult males is additive...i.e. the activity may be "broken" up into "projects" and the greater adult adult males you have the greater "projects" may be performed at as quickly as. in case you think of with reference to the actual concern, it is not trouble-free to have self belief. including greater adult adult males won't inevitably velocity up the challenge. think of development a sidewalk. no count what, you are going to be able to desire to attend till the pavement dries. no count what share all and sundry is @ the activity website, the minimum quantity of time it could take, is the quantity of time it takes for the pavement to dry...under OUR assumption, shall we purely upload greater adult adult males to shrink the "dry time". needless to say this assumption does not make experience right here. it is the "idealized"/"trouble-free"/"easiest" mathematical form. that's a "stable" assumption in case you do no longer drastically exchange the style of adult adult males (the parameter of the undertaking). ok: 30 adult adult males artwork 20 days @ 9 hours an afternoon...for this reason they put in what share hours? 30 adult adult males * 20 days * 9 hours in line with day = 30 * 20 * 9 = six hundred * 9 = 5400 hours!!! now write the equation for the 2nd set of adult adult males: 40 adult adult males * 20 days * x hours in line with day = 40 * 20 * x = 800x the quantity of hours is the comparable: 800x = 5400 hours (from preliminary archives) x = 5400/800 = fifty 4/8 = 6*9 /8 = 3*9/4 = 27/4 hours/day it is 6 hours and 40 5 minutes : 24/4 + 3/4 = 6 hours + 3/4 of an hour) Edit: Why do I particularly have thumbs down? 6 hours and 40 5 minutes IS the answer. I see some human beings fixing the undertaking of "what share days for 40 adult adult males to do the activity of the 30 adult adult males, assuming they artwork the comparable hours/day". it is not what's asked, the hours/day is EXPLICITLY stated to alter. additionally, some all and sundry is wrong approximately despite if there have been initially 20 adult adult males or "thirty" as stated (study greater heavily). 30 adult adult males take 20 days, whilst working 9 hours/day.

Answer 9

4.5 days

Answer 10

4.5 should be it I am not positive though......