TACHS: Math and Ability - TACHS Math

Card 0 of 20

Question

Solve:

Answer

The lines on either side of the negative integer represent that we need to find its absolute value. The absolute value of a number is its real distance from zero on a number line; therefore, we need to calculate how many spaces the number is tot he left of zero on a number line. This number is a distance from zero and will not be negative. All absolute values are positive.

Therefore, the absolute value—or distance from zero—is the following:

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Question

Find the area of a circle with the following radius:

Answer

The area of a circle can be calculated using the following formula:

In this formula the radius is denoted by the variable, .

Substitute in the known variables and solve for the circle's area.

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Question

Which is equal to the radius of a circle with area

Answer

The formula for the area of a circle, given its radius , is . Replace with :

To find the radius , first, divide both sides by :

Now, find the square root of both sides. Since , 20 is the square root of 400, so

.

The radius of the given circle is 20.

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Question

To determine whether a machine on an assembly line is filling bottles with the correct amount of soda, twenty bottles are selected. The tenth bottle and every tenth bottle after that are taken off the line and examined.

This is an example of which kind of sampling?

Answer

The sample in this scenario is selected from the population by choosing obects that occur at regular intervals. That makes this an example of systematic sampling.

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Question

What is the area of a circle that has a diameter of ?

Answer

Recall how to find the area of a circle:

To find the length of the radius, divide the diameter by two.

Now, plug it into the equation for the area of a circle.

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Question

A square has perimeter 24 feet. Give its area.

Answer

The perimeter of a figure is the sum of the lengths of its sides. A square comprises four sides of equal length, so, if the perimeter of the square is 24 feet, then each side has length

feet.

The area of the square is equal to the length of a side multiplied by itself, so the area of this square is

square feet.

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Question

Jennifer wants to wallpaper her room which is made up for four rectangular walls each measuring at feet by feet. If each roll of wallpaper covers square feet of space, how many rolls of wallpaper will Jennifer need?

Answer

Start by finding out the total square footage of wallpaper needed.

Find the area of one wall. Recall that in order to find the area of a rectangle, you must multiply the length by the width.

Since we have four identical walls,

Now divide this by the amount of square feet covered by each roll of wallpaper to find how many rolls are needed.

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Question

Find the circumference of a circle with the following radius:

Answer

In order to find the circumference of a circle we will use the following formula:

In this equation, the variable, , represent's the circle's radius.

Substitute in for the circle's radius.

Simplify and solve.

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Question

Add.

Answer

In order to solve this problem we need to line up the decimal places and add.

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Question

Square 0.44.

Answer

To square a number means to multiply it by itself, so we seek to compute

To multiply two decimal fractions, first multiply, ignoring the decimal points:

Move the (implied) decimal point the number of spaces right equal to the total number of digits right of the decimal points in the factors; this can be seen to be four:

The square of 0.44 is 0.1936.

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Question

Tiffany earns each week. If Mark earns less than Tiffany, what is the sum of their salaries each week?

Answer

Start by finding out how much Mark makes. Since he makes less than Tiffany, we can write the following to find Mark's weekly salary:

Mark must make each week. Now, add together their salaries to find the sum.

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Question

Rachel earns an hour as an assistant in a science lab. How many hour work weeks will she need to work in order to pay for a car that costs ?

Answer

Start by figuring out how much Rachel can earn in each week by multiplying her hourly rate by the number of hours worked each week.

Now, divide the amount she needs to earn by the amount earned each week to find how many weeks she will need to work to earn that amount.

Rachel must work for weeks in order to earn enough for the car.

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Question

Which of the following is equivalent to ?

Answer

Recall that when a number is raised to an exponent, that means we will need to multiply the number the number of times that is equal to the exponent.

Thus, with , this means we will need to multiply by itself four times:

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Question

What is the value of ?

Answer

Start with finding the value of .

In order to add fractions with different denominators, we will need to change one or both denominators first. Notice that is a factor of , which means we can multiply the numerator and the denominator of by to get .

Now, add the two fractions together as they have the same denominator.

Next, solve .

The least common multiple of and is .

Thus,

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Question

Janice's car can travel miles on one gallon of gas. Her car can normally hold gallons of gas, but it is only full. How many miles can Janice travel before the tank is empty?

Answer

Start by finding out how many gallons is currently in Janice's tank.

Since it is only full,

.

The tank only has gallons in it right now. Multiply this by the number of miles traveled per gallon to find how far Janice can travel before the tank is empty.

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Question

Paul can type words per minute. If Josie can type faster than Paul can, how many words can Josie type in minutes?

Answer

Start by finding out Josie's typing rate.

Since she types faster, we can find her rate with the following equation:

Since Josie types at words per minute, we can multiply by the total number of given minutes to find out how many words she can type in the given time frame.

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Question

What is the product of and ?

Answer

Since the question asks for the product, you will need to multiply the two fractions. Recall that in multiplying two fractions, you will multiply the numerators together and then multiply the denominators together.

Next, reduce the fraction.

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Question

What is the difference between and ?

Answer

Since the question asks you to find the difference, you will need to subtract the two fractions:

Start by making both denominators the same. Multiply the numerator and denominator of by to get .

Now, subtract.

Make sure to simplify the answer.

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Question

What is the greatest common factor of and ?

Answer

Start by listing out the factors of .

Next, list out the factors of .

Now, find the largest factor that the two numbers share. In this case, the greatest common factor is .

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Question

Solve the following inequality:

Answer

In algebra an inequality is a relationship that holds through different values of a variable. An inequality is considered to be solved when the variable is isolated to one side of the inequality. We will do this by performing the reverse of the operations that were done to the variable. It is important to note that what is done to one side of the inequality needs to be done on the other.

Let's start by writing the inequality.

Subtract from both sides of the inequality.

Divide each side of the inequality by .

Solve.

The variable is greater than four.

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