Update 2.md

Try to move Hint in 1-E-2

_problems/unit-01/E-using-axioms-to-prove-min-or-max/2.md

@@ -4,7 +4,7 @@ level: 0
 statement: |
     Prove Bonferroni's inequality:  
     $$P(A\cap B)\geq P(A) + P(B) - 1.$$
-    Hint: The addition rule and Kolmogorov's axioms.
+Hint: The addition rule and Kolmogorov's axioms.
 ---
 \\[
     \begin{align}