After the 3rd pick we have: 4 white, 3 red and 8 black marbles.
The probability that the 4th marble is black is:
P ( Black ) = 8 / 15 = 0.5333
After the 4th pick we have: 4 white, 3 red and 7 black marbles.
P ( Red or Black ) = 10 / 14 = 5 / 7 = 0.7143
Answer:

Step-by-step explanation:
Using k as the constant of proportionality.
The expression that expresses the relationship : p varies jointly with the square of d and the cube of u.
Varies jointly means that p will change as 'd' and 'u' will change together with respect to their powers.
We get the expression as:

Answer:
63
Step-by-step explanation:
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