A fair die is tossed repeatedly until a six is obtained. Let X denote the number of tosses required.

The conditional probability that $$X\ge6$$ given $$X>3$$ equals :

An experiment has 10 equally likely outcomes. Let A and B be two non-empty events of the experiment. If A consists of 4 outcomes, the number of outcomes that B must have so that A and B are independent is :

STATEMENT-2: $$\sum\limits_{i = 1}^n {P\left( {{H_i}} \right)} = 1.$$