Find the two numbers whose mean proportion is 12 and the

Report

Report an issue

Name

Email

Message

Submit

Cancel

RRB TC CC Exam (Mumbai) 2006 click here to view all questions

Find the two numbers whose mean proportion is 12 and the third number is 324.

A6 and 8

B4 and 36

C3 and 24

DNone of these

Akilesh Kharvi ? Nov 6 '2016 at 12:37

Answer is : 4 and 36

Let the number be a and b

\(\therefore \sqrt{ab} =12\)

=>\(ab = 12^2=>144 ............(i)\)

Again, \(\frac{a}{b} = \frac{b}{324}\)

\(=> b^2 =324 b\)

\(=324 * \frac{144}{b} .......\text{From (i)}\)

\(=>b^3 = 324 *144\)

\(=> b =\sqrt[3]{324 *144} = 36\)

\(\therefore ab = 144\)

=>\(a = \frac{144}{b} =>\frac{144}{36} = 4\)

\(\therefore \text{a=4 and b}=36\)

All DiscussionsClick here to write answer

Answer is : 4 and 36 Let the number be a and b \(\therefore \sqrt{ab} =12\) =>\(ab = 12^2=>144 ............(i)\) Again, \(\frac{a}{b} = \frac{b}{324}\) \(=> b^2 =324 b\) \(=324 * \frac{144}{b} .......\text{From (i)}\) \(=>b^3 = 324 *144\) \(=> b =\sqrt[3]{324 *144} = 36\) \(\therefore ab = 144\) =>\(a = \frac{144}{b} =>\frac{144}{36} = 4\) \(\therefore \text{a=4 and b}=36\) Akilesh Kharvi ? answered Nov 6 '2016 at 12:37 All Comments

Post your answers here:

Post

Post your comments here:

Message

Post

Cancel