Question

If the three numbers, the ratio of the first and the second is 8 : 9 and that of the second and third is 3 : 4. If the product of the first and third number is 2400, then what is the second number.

• A. 45
• B. 38
• C. 22
• D. None of these

Answer 1

The correct option is A 45

Ratio between first and second number $=8:9$

Let the constant be$x$ .

Then,

First number$=8x$

Second number $=9x$

Ratio between second and third number$=3:4$

Let the constant here be $y$

Then,

Second number$=3y$

Third number$=4y$

Now according to the question,

Product of first and third number$=2400$

$=8xtimes4y=2400$ ......................................1

And here,$9x=3y$ (both equals to second number)

$=y=3x$

Putting this value in equation 1 we get,

$8x\times 4\left(3x\right)=2400$

$x^2=25$

$x=5$

Hence second number $=9\times 5=45$