Answer :
Given the fraction:
[tex]\frac{21}{20}[/tex]You can identify that the numerator is 21 and the denominator is 20.
In order to write the fraction as a percent, you need to:
1. Divide the numerator by the denominator:
[tex]21\div20=1.05[/tex]2. Multiply the Quotient obtained by 100 (this is the same as moving the decimal point two places to the right):
[tex]1.05\cdot100=105\text{\%}[/tex]Hence, the answer is: Option C.