What defines a composite number?
- A. A number with only two factors
- B. A number that is a fraction
- C. A number with more than 2 factors
- D. A number with exactly two factors
Correct Answer: C
Rationale: A composite number is a positive integer greater than one that has more than two factors. Choice A is incorrect because a number with only two factors is a prime number. Choice B is incorrect as being a fraction does not define a composite number. Choice D is incorrect because a number with exactly two factors is a prime number, not a composite number.
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What is the area of the largest circle that can fit entirely inside a rectangle that measures 8 centimeters by 10 centimeters?
- A. 18π cm²
- B. 10π cm²
- C. 16π cm²
- D. 8π cm²
Correct Answer: C
Rationale: The largest circle that can fit inside the rectangle would have a diameter of 8 cm, which means the radius is half of the diameter, thus 4 cm. The area of a circle is calculated using the formula A = πr², where r is the radius. Substituting the radius value into the formula, the area of the circle is π(4)² = 16π cm². Therefore, the correct answer is 16π cm². Choice A (18π cm²), B (10π cm²), and D (8π cm²) are incorrect because they do not represent the area of the largest circle that fits inside the given rectangle.
A homeowner has hired two people to mow his lawn. If person A is able to mow the lawn in 2 hours by herself and person B is able to mow the lawn in 3 hours by himself, what is the amount of time it would take for both person A and B to mow the lawn together?
- A. 5 hours
- B. 2.5 hours
- C. 1.2 hours
- D. 1 hour
Correct Answer: C
Rationale: To find the combined work rate, you add the individual work rates: 1/2 + 1/3 = 5/6. This means that together, they can mow 5/6 of the lawn per hour. To determine how long it would take for both A and B to mow the entire lawn, you take the reciprocal of 5/6, which gives you 6/5 or 1.2 hours. Therefore, it would take 1.2 hours for person A and person B to mow the lawn together. Choice A (5 hours) is incorrect because it does not consider the combined efficiency of both workers. Choice B (2.5 hours) is incorrect as it does not reflect the correct calculation based on the combined work rates of the two individuals. Choice D (1 hour) is incorrect as it doesn't consider the fact that the combined rate is less than the individual rate of person A alone, thus taking longer than 1 hour.
Jacob has $100. She spends 87% of the money. She then invests the remaining amount and earns a profit of 75%. How much money does she now have?
- A. $13.00
- B. $87.00
- C. $22.75
- D. $9.75
Correct Answer: C
Rationale: Jacob spends 87% of $100, which is $87, leaving her with $13. When she invests the remaining $13 and earns a 75% profit, she gains an additional $9.75. Thus, the total amount she now has is $13 (remaining amount) + $9.75 (profit) = $22.75. Choice A is incorrect as it reflects the remaining amount before investing and earning a profit. Choice B is incorrect as it does not account for the profit earned from the investment. Choice D is incorrect as it only considers the profit amount, not the total sum.
What is an exponent?
- A. A number that tells how many times to multiply
- B. A number that is multiplied
- C. A number that divides evenly into another number
- D. A number that represents the square of a number
Correct Answer: A
Rationale: An exponent is a number that indicates how many times a base number is multiplied by itself. The correct answer (A) accurately defines an exponent as a multiplier that shows how many times a number should be multiplied by itself. Choice B is incorrect as it describes a factor rather than an exponent. Choice C is incorrect as it defines a divisor, not an exponent. Choice D is incorrect as it specifically refers to the square of a number, which is not a general definition of an exponent.
A circle has an area of 121π in². Which of the following is the circumference of the circle in terms of pi (π)?
- A. 11π in
- B. 22π in
- C. 44π in
- D. 5.5π in
Correct Answer: B
Rationale: To find the circumference of the circle, we first need to determine the radius. Given that the area of the circle is 121π in², we use the formula for the area of a circle (A = πr²) to find the radius squared. So, r² = 121, which means the radius (r) is 11 in. The circumference of a circle is calculated using the formula 2πr. Substituting the radius value of 11 in, we get 2π(11) = 22π in. Therefore, the correct answer is 22π in. Choice A (11π in), Choice C (44π in), and Choice D (5.5π in) are incorrect because they do not correctly calculate the circumference based on the given area of the circle.