Question

a box contains 100 cards marked from one to hundred if one card is drawn at random from the box find the probability that it bears first is a two digit number second a number which is a perfect square third is number which is divisible by 10

Answer 1

S={1,2,3,4,5,.......,96,97,98,99,100}
n(S)={100}

event a
A={10,11,12.....97,98,99}
n(A)={90}
P(A)=n(A)÷n(S)=90÷100=9/10

event b
B={1,4,9,16,25,36,49,64,81,100}
n(B)=10
P(B)=10÷100=1/10

event c
C={10,20,30,40,50,60,70,80,90,100}
n(C)=10
P(C)=10÷100=1/10