Cards with numbers 2 to 101 are placed in a box. A card is selected at random. Find the probability that the card has

(i) an even number


(ii) a square number


Total number of out comes with numbers 2 to 101, n(s) = 100

(i) Let E1 = Event of selecting a card which is an even number = {2, 4, 6, …100}


[In an AP, l= a + (n - 1)d,


here l = 100,a = 2and d = 2


100 = 2 + (n - 1)2


(n - 1) = 49


n = 50


n (E2) = 9


Required probability


(ii) Let E2 = Event of selecting a card which is a square number


= {4,9,16,25,36,49,64,81,100}


= {(2)2,(3)2,(4)2,(5)2,(6)2,(7)2,(8)2,(9)2,(10)2}



Hence, required probability =


32
1