Question

A number is selected at random from first 100 whole numbers. Find the probability that the number is divisible by 8 or 12

Answer 1

$\bold{experiment : } \\ \\ a \: no. \: is \: selected \: at \: random \: from \: \\ \\ first \: 100 \: whole \: no.$
$\bold{sample \: points : } \\ \\\bold {s = (all \: no. \: from \: 0 \: to \: 99)} \\ \\ \\ \\ no. \: of \: elements \: in \: s : \\ \\ 100 \\ \\\bold {n(s) = 100}$
$\bold{event \: a : } \\ \\ the \: probability \: of \: getting \: a \: no. \: divisible \\ \\ by \: 8 \: or \: 12$
$\bold{a = 8 \:, \: 16 \:, \: 24 \: ,\: 32 \:, \: 40 \: ,\: 48 \: ,\: 56 \:, \: 64 \: ,\: 72 \:, \: 80 \: ,\: 88 \:, \: 96 \: ,\: 12 \: ,\: 36 \:, \: 60 \: ,\: 84 \:)}$

$no. \: of \: elements \: in \: a : \\ \\ 16 \\ \\ \bold{n(a) = 16}$$\bold{probability \: of \: event \: a : }$

n (a) / n (s)

16 / 100

0.16

or

16 %