Question

The table below shows the number of marbles of different colors in a bag:

Stacy draws a marble from the bag randomly without looking. She then draws another marble from the bag without replacing the first one. Which expression shows the probability of drawing white marbles in both the trails?
A. (7/14) * (6/14)
B. (7/14) * (6/13)
C. (7/14) + (6/13)
D. (7/14) + (6/14)

Answer 1

B.

Explanation:

Total number of marbles: 3 + 7 = 4 = 14

Number of white marbles: 7

First drawing of white marble: 7/14

There is no replacement, so after the first white marble has been drawn, now there are 13 marbles left of which 6 are white.

Second drawing of a white marble: 6/13

Probability of drawing a white marble followed by drawing a white marble is:

7/14 * 6/13

Answer: B.

Answer 2

B.
`(7)/(14)*(6)/(13)`

Explanation:

From the table, the number of white marbles is 7.

`n(W)=7`

The total number of marbles is 7+3+4=14

`n(S)=14`

The probability of drawing a white marble is
`(7)/(14)`.

The probability of drawing another white marble without replacing the first one is
`(6)/(13)`

The probability that both marbles are white is

`P(both\:are\:white)=P(W_1)*P(W_2)`

`P(both\:are\:white)=(7)/(14)*(6)/(13)`