Question

50 labourers can dig a pond in 16 days.How many laboures will be required to dig another pond, double in size, in 20 days?

Answer 1

use formula ,
Mi × Di /Wi = Mf × Df /Wf
where M is no of labour D is no of days and W is the part of work

given ,
Mi = 50
Di = 16
Wi = 1
and Mf = ?
Df = 20
Wf = 2

50 x 16 /1 = Mf x 20/2

Mf = 80 labours

Answer 2

As the number of laborers and the number of days are inversely proportional ; hence

For y amount of work :
50×16 = 20x
x = 40

But the amount of work is 2y ,
Hence the number of labourers required
= 2×40
= 80
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