Two persons could fit new windows in a house in 3 days.
(i) One of the persons fell ill before the work started. How long would the job take now?
(ii) How many persons would be needed to fit the windows in one day?
Solution:
Given that, two persons could fit new windows in a house in 3 days
(i) One of the persons fell ill before the work started. How long would the job take now?
If the number of men working decreases, the number of days will increase. Hence they are in inverse proportion.
Let the number of people be x and the number of working days be y.
x₁ = 2, y₁ = 3, x₂ = 1, y₂ = ?
x₁y₁ = x₂y₂
2 × 3 = 1 × y₂
y₂ = (2 × 3)/1
y₂ = 6
Hence the job will be completed in 6 days.
(ii) How many persons would be needed to fit the windows in one day?
If the number of days decreases, then the number of people needed will be increased. Hence they are in inverse proportion.
Let the number of people be y and the number of working days be x.
x₁y₁= x₂y₂
3 × 2 = 1 × y₂
y₂ = (3 × 2)/1
y₂ = 6
6 persons will be needed to fix the window in one day.
☛ Check: NCERT Solutions for Class 8 Maths Chapter 13
Video Solution:
Two persons could fit new windows in a house in 3 days. (i) One of the persons fell ill before the work started. How long would the job take now? (ii) How many persons would be needed to fit the windows in one day?
NCERT Solutions Class 8 Maths Chapter 13 Exercise 13.2 Question 10
Summary:
Two persons could fit new windows in a house in 3 days. (i) One of the persons fell ill before the work started. The job will be completed in 6 days. (ii) 6 persons will be needed to fix the window in one day.
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