I am struggling with this problem from page 402, number 27. The answer seems a bit hard to me. Is there any other technique or strategy to apply here?

**Which three of the following numbers, when multiplied by each other, yield a product less than -1?**

1. \frac{-15}{17}

2. \frac{-18}{19}

3. \frac{23}{-22}

4. \frac{17}{-16}