Gary oak is on a mission to complete his pokedex before ash ketchum. to this end, he starts searching the tall grass for pokemon. assume that there are m pokemon in total and that gary has seen none of them at the start. assume also, that all of the m pokemon are equally likely to appear in the tall grass and each appearance is independent of the previous appearances. let k be the number of encounters required for gary to fill his pokedex (a filled pokedex means that he has seen all m pokemon atleast once). find the expectation and variance of k hint: find the expected number of encounters to find a new pokemon having already seen k(say) pokemon and use this to find the required quantities.