| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.44 |
| Score | 0% | 69% |
The dimensions of this cylinder are height (h) = 8 and radius (r) = 2. What is the surface area?
| 40π | |
| 14π | |
| 120π | |
| 156π |
The surface area of a cylinder is 2πr2 + 2πrh:
sa = 2πr2 + 2πrh
sa = 2π(22) + 2π(2 x 8)
sa = 2π(4) + 2π(16)
sa = (2 x 4)π + (2 x 16)π
sa = 8π + 32π
sa = 40π
If a = 9 and x = 2, what is the value of -6a(a - x)?
| -378 | |
| -288 | |
| -24 | |
| 3 |
To solve this equation, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)
-6a(a - x)
-6(9)(9 - 2)
-6(9)(7)
(-54)(7)
-378
If AD = 25 and BD = 20, AB = ?
| 5 | |
| 7 | |
| 8 | |
| 1 |
The entire length of this line is represented by AD which is AB + BD:
AD = AB + BD
Solving for AB:AB = AD - BDThe dimensions of this cube are height (h) = 4, length (l) = 7, and width (w) = 8. What is the volume?
| 21 | |
| 48 | |
| 18 | |
| 224 |
The volume of a cube is height x length x width:
v = h x l x w
v = 4 x 7 x 8
v = 224
If the area of this square is 36, what is the length of one of the diagonals?
| 9\( \sqrt{2} \) | |
| 8\( \sqrt{2} \) | |
| 6\( \sqrt{2} \) | |
| 2\( \sqrt{2} \) |
To find the diagonal we need to know the length of one of the square's sides. We know the area and the area of a square is the length of one side squared:
a = s2
so the length of one side of the square is:
s = \( \sqrt{a} \) = \( \sqrt{36} \) = 6
The Pythagorean theorem defines the square of the hypotenuse (diagonal) of a triangle with a right angle as the sum of the squares of the other two sides:
c2 = a2 + b2
c2 = 62 + 62
c2 = 72
c = \( \sqrt{72} \) = \( \sqrt{36 x 2} \) = \( \sqrt{36} \) \( \sqrt{2} \)
c = 6\( \sqrt{2} \)