Question

A bag contains 3 Red balls, 4 White balls what is the probability that ball taken out is not white.​

Answer 1

Answer:

pobability of not taking out white ball = 4-3 = 1

Answer 2

Answer:

$\red\bigstar$ Probability that ball taken out is not white = 3/7.

$\red\dag$SOLUTION$\blue\dag$

∵ We know that the total probability of an event = 1

$\boxed{\sf Probability \: of \:getting\: a \:non-white\: ball = 1 - Probability\: of \:getting \:a \:white \:ball}$

Number of red balls in the bag = 3.

Number of white  balls in the bag = 4.

$\boxed{\boxed{\sf Probability \: of \: an\: event = \dfrac{Number \; of\; favorable\; outcomes}{Total \; number \; of \; outcomes} }}$

Here,

Number of favorable outcomes = Number of white  balls in the bag = 4.

Total Number of outcomes = Number of red balls in the bag + Number of white  balls in the bag

$\implies$ Total Number of outcomes = 3 + 4

$\implies$Total Number of outcomes = 7.

✳ Let us assume that the Probability of getting a white ball = P(W).

$\implies \sf P(W) = \dfrac{4}{7}$

Now,

Probability of getting a non - white ball = 1 - P(W)

$\implies \sf 1 - \dfrac{4}{7}$

Here, LCM = 7

$\implies \dfrac{7}{7} - \dfrac{4}{7}$

$\implies \dfrac{7 - 4}{7}$

$\implies \sf \dfrac{3}{7}$