Question

A box contains 7 red marbles, 4 white marbles, and 5 blue marbles. If only white marbles are added to the box, how many must be added to make the probability of drawing a white marble 1/3?

Answer 1

Number of white marble added for same probability is 2

Given:

Number of red marble in box = 7

Number of white marble in box = 4

Number of blue marble in box = 5

Probability of drawing a white marble = 1/3

Find:

Number of white marble added for same probability

Computation:

Assume;

Number of white marble added = a

$Probability = \frac{Number\ of\ favorable\ outcomes}{total\ outcomes}$

So,

$\frac{1}{3} = \frac{(a + 4)}{(7 + 4 + 5 + a)} \\\\\frac{1}{3} = \frac{(a + 4)}{(16 + a)} \\\\16 + a = 3a + 12 \\\\ 2a = 4\\\\a = 2$

Number of white marble added = 2

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https://brainly.com/question/23044118?referrer=searchResults

Answer 2

Answer:

2

Step-by-step explanation: