30 is the value of x given of above quertion
4/7 5/8 6/9 are some possible answers
There's only information to answer question C.
We can only know that 32 marbles were chosen. (yellow and black)
Why?
To answer the first two questions (a and b), we need to know the total number of marbles, so, we can only answer the last question (c).
We know that 7/10 of the 20 yellow marbles were chosen.
So, calculating we have:

Also, we know that 18 black marbles were chosen, so, the total of marbles chosen is equal to 32 (yellow marbles and black marbles)

Have a nice day!
Answer:
1/3(3.14)2^2(24)
Step-by-step explanation:
The volume of a cone is given by the formula;
1/3πr³
Considering the radius is 2 cm and the height is 24 cm (4 times the diameter).
Therefore;
Volume = 1/2(3.14)2²(24)
This can be used to calculate the volume.
C) -1 is the answer to this question