Question

A two-digit number is written at random

(A) Dscribe the sample space

(B) What is the probability that the number is sodd

(C) What is probability that number is larger than 75?

(D) Determine the odds against the event that the number is a multiple of ten.

Answer 1

(A) sample space={10,11,12,13.....98,99}

n(sample space)=90

the sample space of an experiment or random trial is the set of all possible outcomes or results of that experiment.

(B) Odd number={11,13,15.....97,99}

n( odd number)=45

required probability=n(odd number)/n(sample space)=45/90=1/2=0.5

(C) larger than 75={76,77,...98,99}

n(larger than 75)=24

required probability=n(larger than 75)/n(sample space)=24/45=0.5333

(D) multiple of 10={10,20,30,40,50,60,70,80,90}

n(multiple of 10)=9/45=1/5=0.2

odd against (of an event with probability p)=(1-p)/p=(1-0.2)/0.2=4:1