Question

90% of a number is 810, find the number

Answer 1

Answer:

Missing number is $900$ , i.e. $90\%$ of $900$ is $810$ .

Step-by-step explanation:

To find : missing number .

Given : 90% of a number is 810

Solution :

• As per given data we know that , 90% of a number is 810 .
• A percentage is a fraction of an amount expressed as a particular number of hundredths of that amount.
• It is denoted by means %.  
• Fractions can be converted into percentages and vice-versa.
• Percentages are reversible. For example, $30 \%\ of\ 40$ is the same as $40\ \%\ of \ 30$ .
• Let , $x$ be  the number , then according to given condition we write as , $\frac{90}{100} \times x = 810$ .
• Now , by transposing constants at RHS and leaving variable at LHS we find value of $x$ .  

        $\frac{90}{100} \times x = 810\\\\ \frac{9}{10}\times x = 810 \\\\x = \frac{810\times 10}{9}\\\\x = 90\times 10\\\\ x = 900$

Answer 2

Answer:

900

Step-by-step explanation:

Answer is 900, as 9 × 90 = 810