If $36$ men can build a wall of $140m$ long in $21days$, how many men are required to build a similar wall of length $50m$ in $18days$?

Q. If $72$ men can build a wall $280$ m long in $21$ days, how many men will take $18$ days to build a similar type of wall of length $100$ m?

Q. If $20$men can build a wall $56m$long in $6$days, what length of a similar wall can be built by $35$ men in$3$ days?

Q. If $16$ men can build a wall of $52$m long in $25$ days working for $8$ hours a day, in how many days can $64$ men build a similar wall of $260$m long working for $10$ hours a day?