Let us analyse the problem. As the number of men increases, number of days required will decrease. Similarly, if the number of working hours increases the number of days decreases. Hence the number of days is inversely proportional to the number of men and number of working hours. Hence the constant of proportionality is k=195×20×10.
Let x be the number of men, working 13 hours a day, required to finish the job in 15 days. Then 15 is inversely proportional to both x and 13. This gives k=x×13×15. Comparing two expressions for k, we obtain
Number of men required to do the work in 20 days working for 10 hours a day = 195.
Number of men required to do the work in a day working for 10 hours a day = 195 * 20——-> 3900
Number of men required to do the work in a day working for 1 hour a day = 3900*10—–>39000
Number of men required to do the work in 15 days working for 1 hour a day = 39000/15——>2600
Number of men required to do the work in 15 days working for 13 hours a day = 2600/13——->200
200 men required to the work in 15 days working for 13 hours a day.
Answer:
Let us analyse the problem. As the number of men increases, number of days required will decrease. Similarly, if the number of working hours increases the number of days decreases. Hence the number of days is inversely proportional to the number of men and number of working hours. Hence the constant of proportionality is k=195×20×10.
Let x be the number of men, working 13 hours a day, required to finish the job in 15 days. Then 15 is inversely proportional to both x and 13. This gives k=x×13×15. Comparing two expressions for k, we obtain
x=
13×15
195×20×10
=200.
Thus the required number of men is 200.