If 5y - 7 = 13, what is y?
- A. 4
- B. 5
- C. 6
- D. 7
Correct Answer: A
Rationale: To solve the equation 5y - 7 = 13, start by adding 7 to both sides to isolate the term with y: 5y = 20. Then, divide by 5 to solve for y, which gives y = 4. Therefore, the correct answer is A. Choice B, C, and D are incorrect as they do not yield the correct solution when substituted into the equation. It's important to follow the proper steps in solving linear equations to arrive at the correct answer.
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Express 3 5/7 as an improper fraction.
- A. 26/7
- B. 21/7
- C. 22/7
- D. 26/5
Correct Answer: A
Rationale: To convert a mixed number to an improper fraction, multiply the whole number by the denominator of the fraction, then add the numerator. In this case, 3 * 7 + 5 = 21 + 5 = 26. So, 3 5/7 as an improper fraction is 26/7. Choice B (21/7) is incorrect because it represents the original fraction 3 5/7. Choice C (22/7) is incorrect and represents a different fraction. Choice D (26/5) is incorrect and does not reflect the proper conversion of the mixed number to an improper fraction.
Jessica buys 10 cans of paint. Red paint costs $1 per can, and blue paint costs $2 per can. In total, she spends $16. How many red cans did she buy?
- A. 2
- B. 3
- C. 4
- D. 5
Correct Answer: C
Rationale: Let r be the number of red cans and b be the number of blue cans. The total cans equation is r + b = 10. The total cost equation is r + 2b = 16. By solving these equations simultaneously, we find r = 4. Therefore, Jessica bought 4 red cans. Choice A, 2 red cans, is incorrect because it does not satisfy the total cans or total cost condition. Choices B and D are also incorrect as they do not fulfill both conditions simultaneously.
What is the perimeter of a rectangle with a length of 7 cm and a width of 3 cm?
- A. 21 cm
- B. 10 cm
- C. 14 cm
- D. 20 cm
Correct Answer: D
Rationale: To find the perimeter of a rectangle, you add the lengths of all its sides. In this case, the formula for the perimeter of a rectangle is 2*(length + width). Substituting the given values, we get: 2*(7 cm + 3 cm) = 2*(10 cm) = 20 cm. Therefore, the correct answer is 20 cm. Choice A (21 cm) is incorrect because it is the sum of the individual sides rather than the perimeter. Choice B (10 cm) is incorrect because it only represents one side of the rectangle. Choice C (14 cm) is incorrect as it is not the total perimeter of the rectangle.
What is the simplified form of the expression (x^2 + 2x)/(x)?
- A. x + 2
- B. x^2 + 2
- C. x(x + 2)
- D. 1 + 2/x
Correct Answer: A
Rationale: To simplify the expression (x^2 + 2x)/(x), we factor out x from the numerator to get x(x + 2) and then cancel the x in the denominator. This simplifies to x + 2, making choice A the correct answer. Choice B (x^2 + 2) is incorrect as it does not account for the division by x. Choice C (x(x + 2)) is also incorrect as it represents the factored form before cancellation. Choice D (1 + 2/x) is incorrect as it does not simplify the expression correctly.
How will the number 847.89632 be written if rounded to the nearest hundredth?
- A. 847.90
- B. 900
- C. 847.89
- D. 847.896
Correct Answer: A
Rationale: When rounding to the nearest hundredth, we look at the digit in the thousandth place, which is 8. Since the next digit, in the ten-thousandth place, is 9 (greater than or equal to 5), we round up the hundredth place digit. Therefore, 847.89632 rounded to the nearest hundredth is 847.90. Choice B (900) is incorrect as it does not round the number to the nearest hundredth. Choice C (847.89) is also incorrect as it drops the digit 6 in the ten-thousandth place. Choice D (847.896) does not round the number to the nearest hundredth as it retains the thousandth place digit 3.
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