Question

1.A class has 40 students out of which 25 are girls.A student is selected at random as the monitor. Find the probability of selecting: a) a girl as a monitor b) aboy as a monitor.

Answer 1

Given :- ↴

$\sf \: Total \: strength \: of \: the \:class \: is \: 40$

$\sf \: No. \: of \: girls \:= \: 25$

Find :- ↴

$\sf \: No. \: Of \: Boys \: = \: 40\: - \: 25 \: =\: 15\: Boys$

$\sf \: Now,$

[Part A]

$\sf \: So, \sf \: Find \: the \: probability \: of \: selecting \: a \: girl \: as \: monitor$

$\sf \: So, \sf \: Formula \: for \: find \: a \: Probability \: is \sf \: \:\dfrac{No. \:of \: favourable \: outcome}{Total \: no. \:Of \: Outcome}$

$\sf \: No. \: Of \: favourable \: Outcome \: = \: 25$

$\sf \: No. \: Of \: Total \: Outcome \: = \: 40$

$\sf \:Answer \: of \: first \: part \: = \: \dfrac{25}{40} = \dfrac{5}{8}$

[Part B]

$\sf \: So, \sf \: Find \: the \: probability \: of \: selecting \: a \: boy \: as \: monitor$

$\sf \:So, \: Formula \: for \: find \: a \: Probability \: is \sf \: \:\dfrac{No. \:of \: favourable \: outcome}{Total \: no. \:Of \: Outcome}$

$\sf \: No. \: Of \: favourable \: Outcome \: = \: 15$

$\sf \: No. \: Of \: Total \: Outcome \: = \: 40$

$\sf \:Answer \: of \: second \: part \: = \: \dfrac{15}{40} = \dfrac{3}{8}$