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# How many pairs. M p positive integers $$m$$ and $$n$$ satisfy the equation $$\Large \frac{1}{m}$$+$$\Large \frac{4}{n}$$= $$\Large \frac{1}{12}$$Where $$n$$ is an odd integer less than 60?

 A) 7 B) 5 C) 4 D) 3

 D) 3

$$\Large \frac{1}{m} + \frac{4}{n} = \frac{1}{12}$$

$$\Large \frac{1}{m} = \frac{1}{12} - \frac{4}{n}$$

For m to be positive, we have

$$\Large \frac{1}{12} > \frac{4}{n}$$

n > 48

For n = 49, 51 and 57, we get positive integer value of m.

There are three pairs of m and n which satisfy the given equation.

Option (d) is correct.

Part of solved CDS Maths(1) questions and answers : Exams >> CDSE >> CDS Maths(1)

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