Which of these numbers are rational? -7, 0, 5/11, 0.875, 0.1666…, √36, √12, π/2, 3.1416

Step 1. Rational. $-7 = \dfrac{-7}{1}$, $0$, $\dfrac{5}{11}$, $0.875 = \dfrac{7}{8}$, $0.1666\ldots = \dfrac{1}{6}$, $\sqrt{36} = 6$, and $3.1416$, which ends.

Step 2. Irrational. $\sqrt{12} = 2\sqrt{3}$, since $12$ is not a perfect square, and $\dfrac{\pi}{2}$.