Answer:
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)
