Question 1168146
{{{(7C2 + 7C2 + 8C2)/(22C2)}}} = {{{((7!/(2!*5!))+(7!/(2!*5!))+(8!/(2!*6!)))/(22!/(2!*20!))}}} = {{{(21 + 21 + 28)/231}}} = {{{70/231}}} = {{{10/33}}}