[tex]\\ \qquad\quad\sf\longmapsto 30\%\:of\:210[/tex]
[tex]\\ \qquad\quad\sf\longmapsto \dfrac{30}{100}\times 210[/tex]
[tex]\\ \qquad\quad\sf\longmapsto \dfrac{6300}{100}[/tex]
[tex]\\ \qquad\quad\sf\longmapsto 63[/tex]
Step-by-step explanation:
[tex]★→30\% \: of \: 210 \\=>\frac{30}{100} \times 210 \\ =>\frac{6300}{100} \\ => \boxed{63}✓[/tex]