A bag contains 10 w h i t e marbles, 5 g r e e n marbles, 6 y e l l o w marbles. If two different marbles are drawn from the bag , what is the probability of drawing a w h i t e marble then a y e l l o w marble?

1/7

Step-by-step explanation:

If a bag contains 10 white marbles, 5 green marbles, 6 yellow marbles and two marbles are drawn at random, the probability of picking a white marble and then a yellow marble means a white marble was picked first and then followed by yellow marble.

Note that the white marble that was picked first was not replaced. This is a probability question without replacement.

Probability of an event = possible outcome of event/Total outcome of event

Total outcome = total number of marbles = 10+5+6 = 21marbles

If a white marble is selected first, the probability of selecting a white marble will be 10/21.

Since the white ball wasn't replaced, the new total number of marbles will become 21-1 = 20marbles

If yellow marble was then selected out of this 20 marbles remaining, the probability of selecting the yellow marble will be 6/20 {since there are 6yellow marbles}

The probability of drawing a white marble and then a yellow marble will then give us;

10/21×6/20

= 60/420

= 6/42

= 1/7(in its simplified form)

Sample Response: Each base must be treated separately. Since each base is raised to a negative exponent, they should both be in the denominator of the fractions. The simplified form of the expression has 1 in the numerator and r to the 8th power times s to the 5th power in the denominator.