Verified Answer :

well 2/3=0.6666666666666666667  and 10/0,66...=15

You have to divide 10 by \(\frac{2}{3}\)

\(\frac{10}{1}\) ÷ \(\frac{2}{3}\) ⇒ \(\frac{10}{1}\) x \(\frac{3}{2}\)

You use a method called "flip-flop and multiply" where you flip the second fraction to multiply 
\(\frac{10}{1}\) × \(\frac{3}{2}\) ⇒ \(\frac{30}{2}\)

Now divide the numerator (top) by the denominator (bottom)

\(30\) ÷ \(3=15\)

Now lets check:

\(\frac{2}{3} * \frac{15}{1} = \frac{30}{3}\)

\(30\) ÷ \(3=10\) 

Answer: \(\frac{2}{3}\) × \(15=10\)