Conditional probability

If we already know that event B has happened, we can ask what is the probabilty of A in this situation. It is written
P(A|B)
which is read as the probability of A given B. The phrase "given" is often a clue that a conditional probability is involved.

The conditional probability can be calculated using this formula -mathformula2 not MarkupType-
Fatal error: Uncaught Error: Call to undefined method mathformula2::makeTypeDef() in /var/www/vhosts/ent.storkey.uk/html/inc/reporting2.php:365 Stack trace: #0 /var/www/vhosts/ent.storkey.uk/html/inc/dynaPage.php(189): echo_value('conditprobabili...', 'content', Array) #1 /var/www/vhosts/ent.storkey.uk/html/inc/dynaPage.php(742): dynaPage->echo_value('content') #2 /var/www/vhosts/ent.storkey.uk/html/inc/dynaPage.php(179): mainPanel->write('main-panel') #3 /var/www/vhosts/ent.storkey.uk/html/index.php(21): dynaPage->write() #4 {main} thrown in /var/www/vhosts/ent.storkey.uk/html/inc/reporting2.php on line 365