Question

Shweta obtained 18 marks in a test of 25 marks. What was her percentage of marks?
A. \[60\% \]
B. \[66\% \]
C. \[69\% \]
D. \[72\% \]

Answer 1

Hint: We use the concept of percentage to find the percentage of Shweta’s marks. Write marks obtained and total marks in form of fraction and convert the fraction into percentage by multiplying the fraction by 100.
* Percentage is a part of a whole or complete. Percentage is always greater than or equal to 0% and always less than or equal to 100%.

Complete step-by-step answer:
We are given in the statement of question that Shweta obtained 18 marks out of 25 marks.
We are given total marks as 25
Number of marks obtained by Shweta is 18
We know percentage of marks obtained by a student is given by
Number of marks obtained divided by total marks \[ \times 100\]
Substitute the value of marks obtained by Shweta in numerator and total marks in denominator.
\[ \Rightarrow \]Percentage of marks obtained by Shweta\[ = \left( {\dfrac{{18}}{{25}} \times 100} \right)\% \]
We write numerator in terms of its factors so we can cancel out factors from numerator and denominator.
We can write \[100 = 25 \times 4\]
\[ \Rightarrow \]Percentage of marks obtained by Shweta\[ = \left( {\dfrac{{18}}{{25}} \times 25 \times 4} \right)\% \]
Cancel same terms from numerator and denominator
\[ \Rightarrow \]Percentage of marks obtained by Shweta\[ = \left( {18 \times 4} \right)\% \]
Multiply the terms inside the bracket
\[ \Rightarrow \]Percentage of marks obtained by Shweta \[ = \left( {72} \right)\% \]
\[\therefore \]The percentage of marks scored by Shweta is 72%

Option D is the correct answer.

Note: Students might make the mistake of not converting the fraction into simpler form. Keep in mind always cancel all factors between numerator and denominator, else the percentage will not be within 0 and 100. Also, when converting percentage into fraction, we divide the number given in percentage by 100.