Question

Cards marked with number $1,2,3,4,...,25$ are well shuffled and a card is drawn at random. What is the probability that the number of the card is:
1) an even number
2) a multiple of $3$
3) a prime number

Answer 1

$1,2,3,4,...\dots ..25$

(i) P(even)$=\frac{12}{25}\{2,4,6,8,10,12,14,16,18,20,22,24\}$

(ii) $P\left(x3\right)=\frac{8}{25}\{3,6,9,12,15,18,21,24\}$

(iii) n(prime)$=\{1,2,3,5,7,11,13,17,19,23\}$

p(prime)$=\frac{10}{25}$.