We use one whole to take away 1/7 part and 1/3 part to find the remaining part which is shaded:
[tex]1 - \dfrac{1}{7} - \dfrac{1}{3}[/tex]
Convert all the fractions to the same denominator, LCD being 21:
[tex]= \dfrac{21}{21} - \dfrac{3}{21} - \dfrac{7}{21}[/tex]
Combine them:
[tex]= \dfrac{21-3-7}{21}[/tex]
Simplify them:
[tex]= \dfrac{11}{21}[/tex]
[tex]\boxed { \boxed {\text {Answer : } \dfrac{11}{21} \text { of the circle is shaded.}}}[/tex]
