Answer: A) 1260
Step-by-step explanation:
We know that the number of combinations of n things taking r at a time is given by :-

Given : Total multiple-choice questions = 9
Total open-ended problems=6
If an examine must answer 6 of the multiple-choice questions and 4 of the open-ended problems ,
No. of ways to answer 6 multiple-choice questions
= 
No. of ways to answer 4 open-ended problems
= 
Then by using the Fundamental principal of counting the number of ways can the questions and problems be chosen = No. of ways to answer 6 multiple-choice questions x No. of ways to answer 4 open-ended problems
= 
Hence, the correct answer is option A) 1260
The answer would be <span>69.12m.</span>
I believe the answer is C -4
Edit . . . I might have been wrong haha thinking backwards
Answer:


Step-by-step explanation:
Given
Represent volume with v, height with h and radius with r

Required
Determine the values of h and r that uses the least amount of material
Volume is calculated as:

Substitute 432π for V

Divide through by π

Make h the subject:

Surface Area (A) of a cylinder is calculated as thus:

Substitute
for h in 


Factorize:

To minimize, we have to differentiate both sides and set 

Set 

Divide through by 


Cross Multiply


Divide through by 2

Take cube roots of both sides
![r = \sqrt[3]{216}](https://tex.z-dn.net/?f=r%20%3D%20%5Csqrt%5B3%5D%7B216%7D)

Recall that:




Hence, the dimension that requires the least amount of material is when


2x - (3x + 2x)
= -3x
hope this helps !!