Which of the following is the best approximation of 10 times the positive square root of 20?

A. 100.0

B. 44.7

C. 200.0

D. 89.4

Answer Explanation:

We use the calculator to determine the positive square root of 20, which is then multiplied by 20.

Using the calculator,

Multiplying the square root above with 10 becomes

The approximate value is 44.7.

Therefore, the Correct Answer is B.

Q #1: Which of the following is the best approximation of 10 times the positive square root of 20?

A. 100.0

B. 44.7

C. 200.0

D. 89.4

Answer Explanation

We use the calculator to determine the positive square root of 20, which is then multiplied by 20.

Using the calculator,

Multiplying the square root above with 10 becomes

The approximate value is 44.7.
Q #2: Simplify the expression above. Which of the following is correct?

A. 6

B. 8

C. 1

D. 12

Answer Explanation

We follow the order of operations to solve the given expression.

First, we start with the numerator and solve it as follows

[2(3+5*3)]

We start with multiplication in inner brackets, 5*3=15. The expression becomes

[2(3+15)]

Then, we conduct the addition of 3+15=18. Then, the expression yields

[2(18)]=2*18=36

Now, we solve for denominator, which is 12/2=6.

Thus, the expression is reduced into

The expression reduces into 6.
Q #3: The American with Disabilities Act (ADA) requires that the slope of a wheelchair ramp be no greater than 1:12. Which of the following is the minimum length of a ramp needed to provide access to a door that is 2.5 feet above the sidewalk?

A. 25 feet

B. 145 feet

C. 32.5 feet

D. 30 feet

Answer Explanation

The slope represent the ratio between the vertical height to the horizontal length. Let x be the minimum length of the ramp, we can set a proportion with height on the numerator and length on denominator. Then,

Cross-multiply to find the value of x

Thus, the minimum length of the ramp needed is 30 feet to access to a door that is 2.5 feet above the sidewalk.