5 men are hired to complete a job. If one more man is hired, the job can be completed 8 days earlier. Assuming that all the men work at the same rate, how many more man should be hired so that job can be completed 28 days earlier?
Answers
Answer:
5 men are hired to complete a job.
If one more man is hired, the job can be completed 8 days earlier.
:
Let d = original number of days to complete the job
5d = no. of man-days required
:
when one more man is hired
6(d-8) = no. of man-days with six men
therefore
6(d-8) = 5d
6d - 48 = 5d
6d - 5d = 48
d = 48 days when 5 men are hired
5*48 = 240 man-days required to complete the job (same as 6*40)
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Assuming that all the men work at the same rate, How many more men should be hired so that the job can be completed 28 days earlier?
Let m = no. of additional men required
(m+5)(48-28) = 240
(m+5)*20 = 240
20m + 100 = 240
20m = 240 - 100
m = 140/20
m = 7 more men for a total of 12,
:
Check by finding the man-hrs 12*20 = 240 man-hrs completes the job
:
:
It is given that z is directly proportional to x^2 and inversely proportional to sqrt%28y%29
i)Write down an equation connecting x, y and z
z+=+x%5E2%2Fsqrt%28y%29
:
ii) if z = 16 when x = 2 and y = 9
let k = the constant of variation, and write the equation:
z+=+%28kx%5E2%29%2Fsqrt%28y%29
find k
16+=+%28k2%5E2%29%2Fsqrt%289%29 = 16+=+%284k%29%2F3 = 3(16) = 4k
4k = 48
k = 48/4
k = 12
write the equation now as z+=+%2812x%5E2%29%2Fsqrt%28y%29
find the value of z when x =5 and y =4
z+=+%2812%2A5%5E2%29%2Fsqrt%284%29
z+=+%2812%2A25%29%2F2
z = 150
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Step-by-step explanation:
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