Nokea
Solve for x: 2 : 5 :: 64 : x
- A. 32
- B. 70
- C. 128
- D. 160
Correct Answer: C
Rationale: The symbol '::' represents a proportion in which the first pair of numbers is related to the second pair of numbers. To solve for x in the proportion 2 : 5 :: 64 : x, you can set up a proportion equation: 2/5 = 64/x. Cross-multiplying gives you 2x = 5 * 64, which simplifies to 2x = 320. Dividing both sides by 2, you get x = 160. Therefore, x = 128 is the correct answer. Choice A (32) is incorrect as it is not the result of solving the proportion equation. Choice B (70) is incorrect as it is not related to the given proportion. Choice D (160) is a common mistake made by wrongly interpreting the equation; the correct value of x is 128.
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Olivia currently earns $51,200 in her job. If her salary increases by 4% this year, what will her new salary be?
- A. $52,348
- B. $52,736
- C. $53,040
- D. $53,248
Correct Answer: D
Rationale: To find Olivia's new salary after a 4% increase, we calculate 4% of $51,200, which is 0.04 x $51,200 = $2,048. Adding this increase to Olivia's current salary gives us the new salary: $51,200 + $2,048 = $53,248. Therefore, Olivia's salary after the 4% increase will be $53,248. Choices A, B, and C are incorrect as they do not reflect the correct calculation for the new salary after a 4% increase.
The plane is due to land at 6:20 P.M. What would that be in military time?
- A. 620
- B. 1820
- C. 6020
- D. 6200
Correct Answer: B
Rationale: In military time, the afternoon and evening hours are represented by adding 12 to the standard time. Therefore, 6:20 P.M. would be equivalent to 18:20 in military time. To convert from P.M. to military time, simply add 12 hours to the given time. Choice A, '620,' is incorrect because it does not account for converting to military time. Choice C, '6020,' is incorrect as military time uses a 24-hour clock format, and the hour digit should not exceed 23. Choice D, '6200,' is incorrect as it does not follow the military time format where the hour part ranges from 00 to 23.
Positive integers are numbers greater than zero. Which of the following expressions results in the largest positive number?
- A. (2 + 3)^2
- B. 5 x 7 + 2
- C. 10^2 - 4^2
- D. (8 - 1) x 3
Correct Answer: C
Rationale: To find the largest positive number among the expressions, we evaluate each one:
A) (2 + 3)^2 = 5^2 = 25
B) 5 x 7 + 2 = 35 + 2 = 37
C) 10^2 - 4^2 = 100 - 16 = 84
D) (8 - 1) x 3 = 7 x 3 = 21
Therefore, the expression that results in the largest positive number is 10^2 - 4^2, which equals 84. Choices A, B, and D result in smaller numbers.
If the total cost of his purchase was $9.38 and he gave the cashier $20, how much change did he receive?
- A. $0.62
- B. $5.02
- C. $9.38
- D. $10.62
Correct Answer: D
Rationale: To determine the amount of change received, you need to subtract the total cost from the amount given. $20 - $9.38 = $10.62. Therefore, he received $10.62 in change. Option A ($0.62) is incorrect as it is the difference in cents, not dollars. Option B ($5.02) is incorrect as it does not reflect the correct subtraction. Option C ($9.38) is incorrect as it represents the total cost of the purchase, not the change received.
Chun Mei earns a 5% commission on each appliance she sells. If she sells a washer for $749 and a dryer for $689, what will her commission be?
- A. $37.45
- B. $71.90
- C. $149.80
- D. $287.60
Correct Answer: B
Rationale: To calculate Chun Mei's commission, we first find the total sales amount by adding the prices of the washer and dryer: $749 + $689 = $1438. Next, we calculate her 5% commission on this total sales amount: 0.05 * $1438 = $71.90. Therefore, Chun Mei's commission for selling both appliances will be $71.90. Choice B, $71.90, is the correct answer. Choices A, C, and D are incorrect as they do not reflect the accurate calculation of Chun Mei's commission based on the given scenario.