What approximate value will come in place of question mark (?) in the following questions (You are not expected to calculate the exact value).

${12.21}^3-108.02=24.90\%\text{ of }399+?$

The correct answer is 1520.

To find the approximate value of the question mark (?), we round off each decimal number in the given expression to its nearest convenient whole number:

$12.21\approx 12$

$108.02\approx 108$

$24.90\%\approx 25\%$

$399\approx 400$

Substitute these approximate values into the original equation:

${12}^3-108=25\%\text{ of }400+?$

Next, evaluate the individual components:

1. Calculate the cube of 12:

${12}^3=12\times 12\times 12=1728$

2. Calculate 25% of 400:

$25\%\text{ of }400=\frac{25}{100}\times 400=100$

Now, substitute these evaluated values back into the simplified equation:

$1728-108=100+?$

Perform the subtraction on the left-hand side:

$1620=100+?$

Finally, solve for (?):

$?=1620-100$

$?=1520$

Hence, the approximate value that comes in place of the question mark (?) is 1520.