Answer:
1. 0.0469 (4.d.p)
2. 0.05
Step-by-step explanation:
1. First we'll find the probability of drawing a blue marble.
P = (No. favourable events)/(Total events)
In this case it's:
P = (No. blue marbles)/(Total Marbles)
Therefore P(Blue) = 4/16 = 0.25
Now we find the probability of drawing a yellow marble:
The total number will be the same because the blue marble will have been put back.
P(Yellow) = 3/16 = 0.1875
Now, since we are calculating the probability of both happening we multiply together the two individual probabilities to get the combined probability of both:
0.25 x 0.1875 = 0.0469 (4.d.p)
2. The probability of drawing a blue marble is still the same so we can keep that: P(Blue) = 0.25
But this time, the marble is not replaced. This means that the total number of marbles has changed when drawing the yellow marble:
P(Yellow) = 3/15 = 0.2
Now we multiply them together again to find the combined probability of both happening:
0.25 x 0.2 = 0.05
Hope this helped!