A contractor estimates that 3 persons could rewire Jasminder’s house in 4 days. If, he uses 4 persons instead of three, how long should they take to complete the job?

Solution:

Let the number of people be x and the number of days be y.

If the number of persons doing the job increases then, the number of days will increase so they are in inverse proportion.

Two numbers x and y are said to be in inverse proportion when an increase in one quantity decreases the other quantity and vice versa.

xy = k or x = (1/y) k

where k is a constant.

Hence, x₁y₁ = x₂y₂

3 × 4 = 4 × y₂

y₂ = (3 × 4)/4

y₂ = 3

Thus, 4 persons will take 3 days to complete the job.

☛ Check: NCERT Solutions for Class 8 Maths Chapter 13

Video Solution:

A contractor estimates that 3 persons could rewire Jasminder’s house in 4 days. If, he uses 4 persons instead of three, how long should they take to complete the job?

NCERT Solutions Class 8 Maths Chapter 13 Exercise 13.2 Question 6

Summary:

A contractor estimates that 3 persons could rewire Jasminder’s house in 4 days. If, he uses 4 persons instead of three, they will take 3 days to complete the job?

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