Question

A box contains 5 red marbles, 8 white marbles and 4 green marbkes. One marble is taken out of the box at random. What is the probability that the marble taken out will be (i) red (ii) white (iii) not green

Answer 1

$\underline{ \underline{ \mathsf{ \maltese \: Question }}} :$

A box contains 5 red marbles, 8 white marbles and 4 green marbkes. One marble is taken out of the box at random. What is the probability that the marble taken out will be (i) red (ii) white (iii) not green

$\underline{ \underline{ \mathsf{ \maltese \: Answer }}} :$

Total number of marbles in the box :-

$= \: \mathsf \red{5 \: red} \: \bf{ + } \: \mathsf \gray{8 \: white} \: + \: \sf \green{4 \: green}$

$= \red{5} + \gray{8} + \green{4}$

$= 17$

Number of total outcomes in drawing a marble at random from the box = 17

i) Number of red marbles = 5

Number of favourable outcomes in drawing a red ball = 5

Probability of getting a red ball

$\boxed{ \rm{P(R) \: = \: \frac{No.of \: favourable \: outcomes}{No.of \: total \: outcomes} }}$

$\rm{P(R) = \frac{5}{7} }$

______________

(ii) Number of white balls = 8

Number of favourable outcomes in drawing a white marble = 8

Probability of getting a white marble

$\boxed{ \rm{P(W) \: = \: \frac{No.of \: favourable \: outcomes}{No.of \: total \: outcomes} }}$

$\rm{P(W) \: = \: \frac{8}{17} }$

______________

iii) Number of 'non-green' marbles

==> 5 red + 8 white

==> 5 + 8 = 13

Number of outcomes favourable to drawing a non-green marble = 13

Probability of getting a non-green marble

$\boxed{ \rm{P(non - green) \: = \: \frac{No.of \: favourable \: outcomes}{No.of \: total \: outcomes} }}$

$\rm{P(non - green) \: = \: \frac{13}{17} }$

Answer 2

A box contains 5 red marbles, 8 white marbles and 4 green marbkes. One marble is taken out of the box at random. What is the probability that the marble taken out will be (i) red (ii) white (iii) not green