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Two numbers are in the ratio 4:9, If the mean proportional between them is 24, Find. the positive difference between the two numbers.

A30

B25

C15

D20

Answer:

D. 20

Read Explanation:

Two numbers are in the ratio 4 : 9.
Let the numbers be 4k and 9k.

The mean proportional (geometric mean) between them is given as 24.


(4k)(9k)=24\sqrt{(4k)(9k)} = 24

36k2=24\sqrt{36k^2} = 24

6k=24k=46k = 24 \Rightarrow k = 4

So, the two numbers are:

  • (4k = 16)

  • (9k = 36)

Positive difference between the two numbers:


3616=2036 - 16 = \boxed{20}

Answer: 20


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