It took 2 men 5 hours to build an airstrip. working at the same rate, how many additional men could have been hired in order for the job to have taken 1/hour less? (a) two (b) three (c) four (d) six

Answer with explanation:

Time taken by 2, men to build an airstrip = 5 hours

Time taken by 1, men to build the airstrip = 2 × 5

                              =10 hours

Since ,time is inversely proportional to Number of people working and if rate of doing work is Higher time will be less.

Using Unitary method

Number of Men can't be a fraction.So total number of men should be 3 to accomplish the work in 4 Hours.

Earlier 2, men were working to complete the work in 5 days.

Now, 3 men are working to accomplish the work in 4 days.

So,Total number of extra men Added

      = 3-2=1

None of the option , matches with the Answer i got.

i only know the sequence of arithmetic it adds the first is 5+4 then it goes up as it adds to then it is 9+5 then 14+6 then to 20+7 and so on. 5,9,14,20,27,35.

step-by-step explanation: