GMAT Quantitative Reasoning Practice Test 8

We can simplify the given question 'is $15\mathit{Y}=10$ ?' or 'is $\mathit{Y}=\frac{2}{3}$ '?
Statement (1) tells you that $-5\mathit{Y}$ is greater than or equal to $-10,-5\mathit{Y}>-10$, which essentially means, . If , it is unknown whether $\mathit{Y}$ does or does not equal to $\frac{2}{3}$. Statement (1) is insufficient.
Statement 2 tells you that $-6\mathit{Y}$ is smaller than or equal to $-6$ or that $\mathit{Y}>1$. This means that $\mathit{Y}$ could never be less than one, therefore could never be equal to $\frac{2}{3}$. This statement is sufficient.