An equivalent fraction for 2/3 is
1. 2/6
2. 1/3
3. 8/15
4. 10/15

As the given and answers are all fractions, this is merely a trial-and-error method to simplify and see which answers are equivalent to the given fraction. So let us try with all them:

1.) 2/6 = 1/3 (X)
2.) 1/3 is already simplified and is not equivalent to 2/3. (X)
3.) 8/15 is already simplified and is not equivalent to 2/3. (X)
4.) 10/15 = 2/3 (by dividing 5 from both numerator and denominator)

Therefore, the correct answer is 10/15