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