Question

19 men working 15/2 hours a day can finish a job in 21 days.How many hours a day must 45 men work to complete it in 7 days
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Answer 1

As per the data given in the question,

In the above question, it is given that,

19 men working 15/2 hours a day can finish a job in 21 days.

To find hours a day must 45 men work to complete it in 7 days.

One person did one unit of work

So,$19\times \frac{15}{2} \times 21$

we get the 2992.5

So 45 men required hour will be as follow,

$=45\times 7\times x\\=315x$

Thus equating both the equation we get as the work completed will be same.

$2992.5=315x\\x=\frac{2992.5}{315} \\x=9.5$

Hence  45 men required 9.5 hours a day to complete the work in 7 days.

Answer 2

In the above question, it is given that, we have find the value .now we have find the hours a day of $45$ men work to complete in 7 days.

19 men working 15/2 hours a day can finish a job in 21 days.

To find hours a day must 45 men work to complete it in 7 days.

One person did one unit of work

So,$19*\frac{15}{2} *21\\2992.5$

The value of 2992.5

So 45 men required hour will be as follow,

$45*7*X\\=315X$

$2992.5=315X\\X=\frac{2992.5}{315} \\X=9.5$

Further we can write it as $X=9.5$

hence $45$ men work to complete it in $7$days in 9.5 hours.