Question

A bag contains some red and some white balls. A ball is drawn at random from the bag. If the probability of getting a red ball is `2/7`, then the probability of getting a white ball is ______.

Options

• `1/14`

• `5/7`

• `1/7`

• `2/7`

Answer 1

A bag contains some red and some white balls. A ball is drawn at random from the bag. If the probability of getting a red ball is `2/7`, then the probability of getting a white ball is `underlinebb(5/7)`.

Explanation:

Probability of getting a red ball = `2/7`

The total probability of all possible outcomes = 1

There are only two possible outcomes:

Getting a red ball 

Getting a white ball

So, P(Red) + P(White) = 1

Substitute the given value:

`2/7 + P(White) = 1`

Now solve for P(White)

P(White): `1 - 2/7`

Convert 1 into fraction form:

`1 = 7/7`

So, P(White) = `7/7 - 2/7`

= `5/7`