Question

If 5 men working 9 hrs a day can reap a field in 16 days in how many days will 18 men reap the field working 8 hrs ad ay

Answer 1

Solutions :-

Given :
M1 = 5 men
T1 = 9 hours
D1 = 16 days

M2 = 18 men
T2 = 8 hours


We know that,

M1 × T1 × D1 = M2 × T2 × D2
=> 5 × 9 × 16 = 18 × 8 × D2
=> D2 = (5 × 9 × 16)/(18 ×8) = 5


Hence,
If 18 men working 8 hrs a day can reap a field in 5 days

Answer 2

We will use Chain Rule to solve this question.




According to Chain Rule, the work efficiency remains constant.





• $\sf \dfrac{W}{WF \times T}$ = Constant


• Here W = Work Done, WF = Workforce, T = Time.



Let the number of days needed be 'x'.




Applying Chain Rule,



$\sf \dfrac{W}{5 \times 9 \times 16} = \dfrac{W}{18 \times x \times 8}$



Or, x = 5 Days (Answer)