Ncert solutions

Ncert solutions

Grade 8

Direct and Inverse Proportions | Exercise 13.2

Question 10

Q10) 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:

Let the number of days be x.

Here, the number of persons and the number of days are in inverse proportion.

\frac{2}{1}=\frac{x}{3}

x=\frac{3\times2}{1}

x=6 days

(ii) Let the number of persons be y.

Here, the number of persons and number of days are in inverse proportion.

\frac{2}{x}=\frac{1}{3}\Rightarrow x\times1=2\times3

\Rightarrow x=\frac{2\times3}{1}=\ 6

(Let the number of days be x.window in one day.

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subject-cta

Question 10

Q10) 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:

Let the number of days be x.

Here, the number of persons and the number of days are in inverse proportion.

\frac{2}{1}=\frac{x}{3}

x=\frac{3\times2}{1}

x=6 days

(ii) Let the number of persons be y.

Here, the number of persons and number of days are in inverse proportion.

\frac{2}{x}=\frac{1}{3}\Rightarrow x\times1=2\times3

\Rightarrow x=\frac{2\times3}{1}=\ 6

(Let the number of days be x.window in one day.

Still have questions? Our expert teachers can help you out

Book a free class now

Want to top your mathematics exam ?

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Book a free class now
subject-cta
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