There will be 23 layers of brick, because 7500/321 = 23 with 117 leftover.
Answer:

And the best answer on this case would be:
b) m = 4.635
Step-by-step explanation:
Let X the random variable of interest and we know that the confidence interval for the population mean
is given by this formula:

The confidence level on this case is 0.9 and the significance 
The confidence interval calculated on this case is 
The margin of error for this confidence interval is given by:

Since the confidence interval is symmetrical we can estimate the margin of error with the following formula:

Where Upper and Lower represent the bounds for the confidence interval calculated and replacing we got:

And the best answer on this case would be:
b) m = 4.635
A=10x(15x)-p(4x)^2
A=150x^2-16px^2
A=(150-16p)x^2
When she cubed the number of flowering plants that means p^3 so the answer is not A or B
now take a look at C or D
both are p^3 + 2 which is right now lets solve it:
3^3 + 2 = 27 +2 = 29
so the answer is D :)))
i hope this is helpful
have a nice day