$25\times 8.16+{\left(24\right)}^2-?={\left(9\right)}^3$

Find the value of question (?) mark in following questions.

The correct option is 51.

We need to find the value of the question mark (?) in the following equation:

$25\times 8.16+{\left(24\right)}^2-?={\left(9\right)}^3$

Let the unknown value of the question mark (?) be denoted by x.

Step 1: Calculate the multiplication term
We multiply 25 by 8.16:
$25\times 8.16=204$

Step 2: Calculate the square term
We find the square of 24:
${\left(24\right)}^2=24\times 24=576$

Step 3: Calculate the cube term
We find the cube of 9:
${\left(9\right)}^3=9\times 9\times 9=729$

Step 4: Substitute the values back into the equation
Replacing these values into the original expression gives:
$204+576-x=729$

Step 5: Solve for x
First, add 204 and 576:
$780-x=729$

Now, isolate x:
$x=780-729$
$x=51$

Thus, the value of the question mark (?) is 51.