Could someone please check my math questions? any help will be greatly appreciated!

Question

Questions~
16. A car’s speed before a sudden stop can be estimated by the formula
S = √(30gk) , where
S = speed of the car in mph,
g = drag factor, and
k = length of skid mark in feet.

The drag factor during a recent crash was 0.8. What was the approximate speed of the car if it created skid marks 93 feet long?
a. 34 mph

b. 47 mph

c. 68 mph

d. 85 mph
Answer~ d
17. The length of a rectangle is (3x – 7) inches and its width is (x + 5) inches. Find an expression for the perimeter of the rectangle.

a. 4x - 35

b. 4x - 2

c. 8x - 4

d. 8x - 35
Answer~c

18. Which of the following sets does not contain only rational numbers?

a. -5, p/2, 0.5, -0.12

b. -0.4, -0.3333.. , 6.8, 6.888…

c. 11/7, 5/4, 8/5, 32/19

d. ½, ¼, 1/8, 1/16
Answer~ b

19. What is the value of (-3)^
x when x = 3.

a. -27

b. -9

c. 9

d. 27
Answer~a


20. Which rational number lies between √10 and √12 ?

a. 45/14

b. 47/13

c. 47/19

d. 52/17
Answer~a


21. A shelter has enough food to feed an average of 80 hungry people a day for 14 days. If an average of 32 people are at the shelter each day, how long will the food last?

a. 5.6 days
b. 35 days
c. 183 days
d. 200 days
Answer~b

22. Which of the following numbers is a solution of the inequality 9 – x > 2? (NOTE: the > sign has a line under it)
a. 7
b. 8
c. 9
d. 10
Answer~ a
23. What is the value of the expression [(5)(9) / x] + 6x when x = -3?
a. -33
b. -9
c. 3
d. 33
Answer~b
24.What is the solution of 30| x | = 10?
a. -3 and 3
b. 3
c. 1/3
d. -1/3 and 1/3
answer~ d
25. Which step can you use to solve the equation 3x = -12?
a. Divide each side by -12.
b. Divide each side by 3.
c. Multiply each side by -12.
d. Multiply each side by 3.
Answer ~ I think it's a or c