Question

20 labourers can dig a pond in 12 days. How many days will it take 16 labourers to dig the same pond?

Answer 1

as the no. of workers increases the no. Of days decreases

so it is the example of inverse variation

product remains constant

Let no. Of days be x

so

20 × 12 = K

16 × x = K

20 × 12 = 16 × x

x = 20 × 12 / 16

x = 5 × 3

x = 15

so 16 Labour's can complete the work in 15 days

Answer 2

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Let the number of days take by 16 labourers to dig the same pond be x

Given that number of days taken by 20 labour to dig a pond = 12

therefore, work done by 20 labour in 12 days = work done by 16 labour in x days

$\implies20 \times 12 = 16 \times x$

$\implies \: x = \frac{20 \times 12}{16} = 15$

Hence, 16 labour will dig the same pond in 15 days