Question

The only contents of a bag are 4 red balls and 6 blue balls. What is the probability that two balls drawn at random from the bag will be red if the first ball drawn is not replaced

Answer 1

See below ~

Explanation:

P (first red) :

⇒ Original number of red balls / Total

⇒ 4 / 10

⇒ 0.4

⇒ 40%

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Remember the first ball drawn is NOT replaced.

P (second red) :

⇒ Original number of red - 1 / Total - 1

⇒ 4 - 1 / 10 - 1

⇒ 3/9

⇒ 33%