Five cards are drawn at random from a pack. The probability that they are of the same colour is

Five cards are drawn at random from a pack

$\mathrm{n}\left(\mathrm{S}\right){=}^{52}{C}_5$

E=Event of getting 5 cards  are of the same colour 

$\mathrm{n}\left(\mathrm{E}\right)=2\left({ }^{26}{C}_5\right)$

$\mathrm{P}\left(\mathrm{E}\right)=\frac{2\left({ }^{26}{C}_5\right)}{{ }^{52}{C}_5}=\frac{2\times 26\times 25\times 24\times 23\times 22}{52\times 51\times 50\times 49\times 48}=\frac{23\times 11}{51\times 49\times 2}=\frac{253}{4998}$