Percentages MCQ Quiz - Objective Question with Answer for Percentages - Download Free PDF

Given:

First increase (r1) = 20%

Second decrease (r2) = -15%

Formula used:

Overall % change = r1 + r2 + (r1 × r2)/100

Calculations:

Overall % change = 20 + (-15) + (20 × -15)/100

⇒ Overall % change = 20 - 15 - 300/100

⇒ Overall % change = 5 - 3 = 2%

∴ The overall percentage change in the price is 2%.

The initial price increase of makes the price . A subsequent decrease results in . Therefore, the final price is , showing that the combination of increases and decreases results in a net increase of .

The correct answer is option 1. The sale price is 85% of the original price. To find this, multiply by 0.85. Hence, the expression is . Option 2 implies the sale price is 850% of the original price, which is incorrect. Option 3 implies the sale price is 8.5% of the original price, which is incorrect. Option 4 implies the sale price is 8500% of the original price, which is incorrect.

To find q, we start with the equation: . Dividing both sides by 80 gives . Subtracting 1 from both sides, we have . Multiplying by 100 gives . Thus, the value of q is 500.

Initially, the population is . A reduction each hour means after the first hour, the population is . After the second hour, it becomes . Then, an increase of means the population is . Thus, is of the original population, which is approximately .

Choice A is correct. It's given that the value of the comic book increased by 167% from the end of 2011 to the end of 2012. Therefore, if the value of the comic book at the end of 2011 was a dollars, then the value, in dollars, of the comic book at the end of 2012 was , which can be rewritten as 1x + 1.67x, or 2.67. It's also given that the value of the comic book decreased by 16% from the end of 2012 to the end of 2013. Therefore, the value, in dollars, of the comic book at the end of 2013 was , which can be rewritten as 2.67x - (2.67x) (0.16), or 2.2428x. Thus, if the value of the comic book at the end of 2011 was dollars, and the value of the comic book at the end of 2013 was 2.2428x dollars, then from the end of 2011 to the end of 2013, the value of the comic book increased by 2.2428x-1x, or 1.2428x, dollars. Therefore, the increase in the value of the comic book from the end of 2011 to the end of 2013 is equal to 1.2428 times the value of the comic book at the end of 2011. It follows that from the end of 2011 to the end of 2013, the net percentage increase in the value of the comic book was (1.2428) (100) %, or 124.28%.
Choice B is incorrect and may result from conceptual or calculation errors.
Choice C is incorrect. This is the difference between the net percentage increase in the value of the comic book from the end of 2011 to the end of 2012 and the net percentage decrease in the value of the comic book from the end of 2012 to the end of 2013, not the net percentage increase in the value of the comic book from the end of 2011 to the end of 2013.
Choice D is incorrect. This is the net percentage increase in the value of the comic book from the end of 2011 to the end of 2013, if the value of the comic book increased by 167% from the end of 2011 to the end of 2012 and then increased, not decreased, by 16% from the end of 2012 to the end of 2013.

The correct answer is .88. It's given that the number a is 60% greater than the positive number b. Therefore, , which is equivalent to a = (1 + 0.60)b, or a = 1.60b. It's also given that the number c is 45% less than a. Therefore, , which is equivalent to c = (1 -0.45)a, or c = 0.55a. Since a = 1.60b, substituting 1.606 for a in the equation c = 0.55a yields c = 0.55(1.60b), or c = 0.886. Thus, the number cis 0.88 times the number b. Note that .88 and 22/25 are examples of ways to enter a correct answer.

Choice C is correct. It's given that 37% of the items in a box are green. Let x represent the total number of 100 100 items in the box. It follows that , items in the box are green. It's also given that of those, 37% are also rectangular. Therefore, , items in the box are green rectangular items. It's also given that of the green rectangular items, 42% are also metal. Therefore, , items in the box are rectangular green metal items. The number of the items in the box that are not rectangular green metal items is the total number of items in the box minus the number of rectangular green metal items in the box. Therefore, the number of items in the box that are not rectangular green metal items is - 0.057498x, or 0.942502x. The percentage of items in the box that are not rectangular green metal items is the percentage that 0.942502x is of x. If p% represents this percentage, the value of p is Of the given choices, 94.25% is closest to the percentage of items in the box that are not rectangular green metal items.
Choice A is incorrect and may result from conceptual or calculation errors.
Choice B is incorrect and may result from conceptual or calculation errors.
Choice D is incorrect and may result from conceptual or calculation errors.

The correct answer is .0014. It's given that a certain type of substance can contain a maximum of 0.001% phosphorus by mass to meet a set of standards. If a sample of the substance has a mass of 140 grams, it follows that the maximum mass, in grams, of phosphorus the sample can contain to meet the standards is  which is equivalent to (0.00001)(140), or 0.0014. Note that .0014 and 0.001 are examples of ways to enter a correct answer.

The correct answer is 47.25. It's given that the number w is 110% greater than the number z. It follows that . It's also given that the number z is 55% less than 50. It follows that which yields z = 22.5. Substituting 22.5 for z in the equation w = 2.1% yields w = 2.1(22.5), which is equivalent to w = 47.25. Therefore, the value of w is 47.25. Note that 47.25 and 189/4 are examples of ways to enter a correct answer. 

The correct answer is .48. It's given that the number a is 70% less than the positive number b. Therefore, , which is equivalent to a = (1 - 0.70)b, or a = 0.30b. It's also given that the number c is 60% greater than a. Therefore, , which is equivalent to c = (1 + 0.60)a, or c = 1.60a. Since a = 0.30b, substituting 0.30b for a in the equation c = 1.60a yields c = 1.60(0.30b), or c = 0.48b. Thus, c is 0.48 times b. Note that .48 and 12/25 are examples of ways to enter a correct answer.

Choice A is correct. The percentage of adults aged 18–50 who responded “warm” is , or about 58.9%. The percentage of adults aged 51 years or greater who responded “warm” is , or about 55.0%. The difference between 58.9% and 55.0% is 3.9%. Of the answer choices, 4% is closest to this number. 
Choices B, C, and D are incorrect and may result from calculation errors. 

Choice B is correct. The percent increase from 2012 to 2013 was , or 5%. Since the percent increase from 2012 to 2013 was estimated to be double the percent increase from 2013 to 2014, the percent increase from 2013 to 2014 was expected to be 2.5%. 
Therefore, the number of subscriptions sold in 2014 is expected to be the number of subscriptions sold in 2013 multiplied by (1 + 0.025), or 5,880 (1.025) = 6,027.
Choice A is incorrect and is the result of adding half of the value of the increase from 2012 to 2013 to the 2013 result. Choice C is incorrect and is the result adding twice the value of the increase from 2012 to 2013 to the 2013 result. Choice D is incorrect and is the result of interpreting the percent increase from 2013 to 2014 as double the percent increase from 2012 to 2013. 

The correct answer is 8. The 6 students represent (100 -15 - 45 - 25)% = 15% of those invited to join the committee. If x people were invited to join the committee, then 0.15x = 6. Thus, there were  people invited to join the committee. It follows that there were 0.45(40) = 18 teachers and 0.25(40) = 10 school and district administrators invited to join the committee. Therefore, there were 8 more teachers than school and district administrators invited to join the committee.