I think it is b but wait till someone else answers to
Answer:

Step-by-step explanation:
The formula of a volume of a sphere:

R - radius
We have R = 3 ?. Substitute

If the radius is 30, then the volume is:

If 30 is the length of diameter, then the radius R = 30 : 2 = 15.
Therefore the volume:

Answer:
D. 7 (6x+7)
Step-by-step explanation:
Factor 7 out of 42x + 49
Answer:
3.6%
Step-by-step explanation:
Because the two events are independent, their probabilities are multiplied, so the probability of a student being born in March and having a blood type of O+ is 9% * 40% = 0.09 * 0.40 = 0.036 = 3.6%