Question

15 cards numbered 1 to 15 are put in a box and mixed thoroughly one card is drawn from the box what is the probability that the number on the card is
i) even
ii) a prime
iii) divisible by 3
iv) divisible by 2
v) divisible by 5

Answer 1

from 1-15 we have

even -7 cards

prime-6 cards

divisible by 3-5 cards

divisible by 2-7 cards

$1) \frac{no.of \: favourable \: outcomes}{total \: no.of \: outcomes} \\ \frac{7}{15} \\ 2)\frac{no.of \: favourable \: outcomes}{total \: no.of \: outcomes} \\ \frac{6}{15} \\ 3)\frac{no.of \: favourable \: outcomes}{total \: no.of \: outcomes} \\ \frac{5}{15} = \frac{1}{3} \\ 4)\frac{no.of \: favourable \: outcomes}{total \: no.of \: outcomes} \\ \frac{7}{15} \\ 5)\frac{no.of \: favourable \: outcomes}{total \: no.of \: outcomes} \\ \frac{3}{15} = \frac{1}{3}$

divisible by 5-3 cards