Question

q) a certain number of men can finish a piece of work in 10 days. if however there were 10 men less it will take 10 days more for the work to be finished. how many men were there originally? (a) 110 men (b) 130 men (c) 100 men (d) none of these

Answer 1

1. let x be the workers who can complete work in 10 days
2. If there were 10 men less then it would take 10 more days i.e, 20 days
3. Now here comes the formula:

• (M1*D1*H1)/W1=(M2*D2*H2)/W2
• where M1 is no.of workers there r originally
•            M2                                      after some period of time
•            D1 is  no.of days it would take to complete work with M1 workers
•             D2                                                                                    M2 workers
• Similarily H1 and H2 r no.of hours to complete work
• w1 is amount of work done with m1
• w2                                                    m2

1. hence from this formula we get (x*10)=(x-10)*20
2. from this we get x=20 which is 20 men worked originally
3.