Question

A shop sells $6$ different flavors of ice-creams. In how many ways can a customer choose $4$ ice-cream cones if they are all of different flavours?

Answer 1

$6$ icecreams of $4$ different flavours are chosen

${=}^6{C}_4$

$=\frac{6!}{4!2!}$

$=\frac{6\times 5\times 4!}{4!\times 2}$

$=15$ ways.