is means equal
x percent is x/100
of means multiplication
So translating what you were given:
[tex]\sf{10=\frac{x}{100}\times60}[/tex]
Solve for x
[tex]\sf{10=\frac{60x}{100}}[/tex]
Simplify it
[tex]\sf{10=\frac{3x}{5}}[/tex]
Multiply both sides by 5/3 to isolate x
[tex]\sf{x=\frac{50}{3}}[/tex]
Your final answer is
[tex]\Huge{\boxed{\bf{10~is~16.67~percent~of~60}}}[/tex]