An Experiment Consists of Picking at Random a Bit String $p \left( E _ { 2 } \mid E _ { 3 } \right)$

Short Answer

an experiment consists of picking at random a bit string of length five. Consider the following events:
E1: the bit string chosen begins with 1;
E2: the bit string chosen ends with 1;
E3: the bit string chosen has exactly three 1's.
-Find $p \left( E _ { 2 } \mid E _ { 3 } \right)$ .