Question

A card marked with numbers 3, 4 , 5, ........... 50 placed in a bag and mixed thoroughly one card is drawn at random from the bag find the probability that numbers on the card drawn is

A) Divisible by 7

B) A perfect square

C) A multiple of 3


(Class - 10th Sample paper issued by CBSE)

Answer 1

a) the total nos divisible by 7 from 3 to 50 are 7
the total no from 3 to 50 are 48
so the probability of getting a number divisible by 7 is 7/48
b) total perfect squares from 3 to 50 are 6
total no from 3 to 50 48
so probability is 6/48
which is 1/8
c) total no of multiples of 3 from 3 to 50 are 16
total nos 3 to 50 are 48
so probability is 16/48
which is 1/3

hope this will help

Answer 2

TOTAL NO. OF CARD ={3,4,5.....50}

n(S)=48

(1) ..let E BE THE events getting of card divisible by 7

E={7,14,21,...49}

n(E)=7
P(E)=7/48
(2) ..

let q be the event of getting of card perfect square


q= {4,9,25,36,49}

n(q)=6

P(q) =6/48
=>1/8


(3).let S be event of getting cards multiple of 3
S={3,6,9,12,48}
n(S)=16

P(S)=16/48
=>1/3

I HOPE ITS HELP YOU DEAR,
THANKS