Question

Cards numbered 7 to 40 were put in a box. Poonam selects a card at random. what is the probability that poonam selects a card which is a multiple of 7

Answer 1

Multiple Of 7 between 7-40

=7,14,21,28,35

There are Total 5 multiples of 7 between 7-40.

Total Cards=40-7=33
In including 7=34

Total Card=34

$\boxed{\mathbf{Probability\implies\frac{Favourable\: Outcomes}{Total\: Outcomes}}}$

Favourable Outcomes=5

Total Outcomes=34

$\boxed{\mathbf{Probability\:(Multiple\:7)=\frac{5}{34}}}$

Answer 2

Cards numbered 7 to 40 were put in a box.

so, total number of cards in the box = 40 - 7 + 1= 34

[ because we have to include card numbered 7 so, we add 1 ]

so, sample space, n(S) = total number of cards

we have to find probability of a card which is a multiple of 7.

so, selected cards are ; 7, 14, 21, 28, 35.

hence, favourable outcomes, n(E) = 5

we know,

probability = favourable outcomes/sample space

or, P(E) = n(E)/n(S) = 5/34

hence, probability of a card which is multiple of 7 = 5/34