A circle has an area of 81π in2. Which of the following is the circumference of the circle in terms of pi ( π)?
A. 4.5 π in
B. 14 π in
C. 18 π in
D. 9 π in
we need to find the circumference of the circle from the given area.
The first step is to find the radius of the circle using the given area. Let r be the radius of the circle, then:
Substituting the value of area in the above equation becomes
Dividing both sides by pi and taking square root on both sides yields
Now, we know the radius of circle to be 9 in, the circumference of the circle becomes,
in.
Therefore, the Correct Answer is C.
More Questions on TEAS 7 Math
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Q #1: Which of the following is the median of the date set below? -6, 8, -4, 12, 1
A. 8
B. 1
C. -4
D. 12
Answer Explanation
The median of the data set is the number that falls in the middle position after arranging the numbers in the data set in the ascending order.
-6, -4, 1, 8, 12
There are 5 numbers in the given data set, therefore the median falls in the third position from either side. Inspecting the data set, 1 fall in the third position, which is the median for the given data set.
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Q #2: Which of the following is the decimal equivalent of 9/20?
A. 0.45
B. 3.4
C. 3.57
D. 0.18
Answer Explanation
9/20 is the same as 9 divided by 20, which is evaluated 9÷20. The value becomes 0.45.
Thus, 9/20 is equal to 0.45.
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Q #3: Which of the following is the decimal form of 67.9%?
A. 67.9
B. 6,790
C. 0.679
D. 8.75
Answer Explanation
percentages are fractions with denominator equal to 100. Then, in decimal form:
The decimal form of 67.9% is 0.679.
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Q #4: A recipe calls for 3.4 teaspoons of milk. 1 teaspoon equals approximately 5 mL. Which of the following is the correct amount of milk in mL?
A. 16.8 mL
B. 17.0 mL
C. 10.5 mL
D. 6.8 mL
Answer Explanation
we are asked to find the amount of milk in mL using the given information.
If we let x represent the amount of milk in mL, we set up a proportion with number of teaspoons on the numerator and amount in mL in the denominator.
A recipe of 3.4 teaspoons is equal to 17.0 mL.
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Q #5: A baker is using a cookie recipe that call for 5 ¼ cups of flour to yield 40 cookies. How much flour will the baker need to make 120 cookies using the same recipe?
A. 15 ¾ cups
B. 5 7/8 cups
C. 14 1/8 cups
D. 15 ¼ cups
Answer Explanation
we are tasked to find the number of cups of flour that will be used to make 90 cookies.
This is a proportion equation, and letting x be the number of cups of flour we set the equation as follows:
Solve the value of x by cross-products
Next, we convert the mixed fraction into improper fraction in order to carry out multiplication
The baker needs 15.75 cups of flour to make 120 cookies. 15.75 in mixed fraction is
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Q #6: Which of the following is the best approximation of 6 times the positive square root of 42?
A. 60.3
B. 44.7
C. 30.0
D. 38.9
Answer Explanation
In this case, we use a calculator to estimate the positive square root of 42.
Then, multiplying the square root above with 6 becomes
Then, the approximate value of 6 time the positive square root of 42 is 38.9.
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Q #7: 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 1.5 feet above the sidewalk?
A. 22 feet
B. 19.5 feet
C. 32.5 feet
D. 18 feet
Answer Explanation
The slope represents the ratio of rise to run. Let p be the minimum length of the ramp, we can set a ratio equation as follows. Then,
The minimum length of the ramp needed is 18 feet to access to a door that is 1.5 feet above the sidewalk.
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Q #8: -3/5, -0.9, -1.9, -8/3 Of the number listed above, which number is the greatest?
A. -3/5
B. -0.9
C. -1.9
D. -8/3
Answer Explanation
To answer this question, we need to convert the numbers into a similar form. Converting decimal numbers into fraction is appropriate to finding the greatest number.
-0.9 becomes 9/10
-1.9 becomes 19/10
Now we find the LCM of the denominators of the four fractions. The LCM of 5, 10 and 3 is 30. Multiply each fraction with the LCM to compare the fractions.
-3/5*30=-18
-9/10*30=-27
-19/10*30=-57
-8/3*30=-24
The greatest number is -18, meaning -3/5 is the greatest number.
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Q #9: Simplify the expression above. Which of the following is correct?
A. 6
B. 18
C. 9
D. 22
Answer Explanation
To simplify this expression, we follow the order of operations as follows:
First, we start with the numerator and solve it as follows
[2(6+3*9)]
We start with multiplication in inner brackets, 3 * 9 = 27. The expression becomes
[2(6+27)]
Then, we carry out the addition of 6+27=33. Then, the expression yields
[2(33)]=2*33=66
Now, we solve for denominator, which is 6/2=3.
Thus, the expression is reduced into
The expression reduces into 22.
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Q #10: A bucket containing 3 3/5 gallons of water is 2/3 full. How many gallons of water is in one fully filled bucket?
A. 13/15
B. 6 7/15
C. 8 2/5
D. 5 2/5
Answer Explanation
we are asked to find the number of gallons a full tank holds. A full tank is treated as 1 whole.
Letting x be the number of gallons in full tank and setting the proportion equation with the number of gallons on the numerator and fraction of tank on denominator as follows.
Convert the mixed fraction into proper fraction and cross-multiply to find the value of x.
x 1 full tank=185 gallons23full tank
A full tank holds 27/5 gallons, which when converted to a mixed fraction is 5 2/5.
