Get Started

Top 100 Aptitude Questions and Answers for Competitive Exams

7 months ago 104.6K Views
Q :  

In an examination, 34% of the students failed in mathematics and 42% failed in English. If 20% of the students failed in both subjects, then find the percentage of students who passed in both subjects.

(A) 40%

(B) 41%

(C) 43%

(D) 44%

Correct Answer : D
Explanation :

To find the percentage of students who failed in at least one subject (A or B or both), we can use the principle of inclusion-exclusion:

Percentage of students who failed in at least one subject (A or B or both) = Percentage of students who failed in M + Percentage of students who failed in E - Percentage of students who failed in both subjects

= M + E - B

= 34% + 42% - 20% = 76% - 20% = 56%

So, 56% of the students failed in at least one subject.

Now, to find the percentage of students who passed in both subjects, we subtract the percentage of students who failed in at least one subject from 100%:

Percentage of students who passed in both subjects = 100% - Percentage of students who failed in at least one subject = 100% - 56% = 44%

Therefore, the percentage of students who passed in both subjects is 44%.


Q :  

The numbers of boys and girls in a college are in the ratio of 3:2. If 20% of the boys and 25% of the girls are adults, the percentage of students, who are not adults, is

(A) 58%

(B) 60(1/5)%

(C) 78%

(D) 83(1/3)%

Correct Answer : C
Explanation :

To solve this problem, let's first represent the number of boys and girls in terms of a common variable. Let's say there are 3x boys and 2x girls.

Given that 20% of the boys and 25% of the girls are adults, we can calculate the number of adults among them.

Number of adult boys = 20% of 3x = (20/100) * 3x = 0.2 * 3x = 0.6x Number of adult girls = 25% of 2x = (25/100) * 2x = 0.25 * 2x = 0.5x

So, the total number of adult students = 0.6x (boys) + 0.5x (girls) = 1.1x

Now, the total number of students in the college = 3x (boys) + 2x (girls) = 5x

The percentage of students who are not adults = (Total number of non-adult students / Total number of students) * 100%

Since the total number of adult students is 1.1x, the total number of non-adult students = Total number of students - Total number of adult students = 5x - 1.1x = 3.9x

So, the percentage of students who are not adults = (3.9x / 5x) * 100% = (3.9/5) * 100% = 78%

Therefore, the percentage of students who are not adults is 78%.


Q :  

7,500 is borrowed at C.I. at the rate of 2% for the first year, 4% for the second year, and 5% for the third year. The amount to the paid after 3 years will be

(A) 8235.00

(B) 8432.00

(C) 8520.20

(D) 8353.80

Correct Answer : D

Q :  

Imran borrowed a sum of money from Jayant at the rate of 8% per annum simple interest for the first four years, 10% per annum for the next six years, and 12% per annum for the period beyond 10 years. If he pays a total of Rs. 12,160 as interest only at the end of 15 years, how much way did he borrow?

(A) 8000

(B) 10,000

(C) 12,000

(D) 9,000

Correct Answer : A
Explanation :

To find the amount Imran borrowed, let's break down the problem step by step.

Let's denote the principal amount borrowed by Imran as P.

For the first four years, the simple interest is calculated at the rate of 8% per annum. So, the interest for the first four years = P * 8% * 4 = 0.08P * 4 = 0.32P

For the next six years, the simple interest is calculated at the rate of 10% per annum. So, the interest for the next six years = P * 10% * 6 = 0.1P * 6 = 0.6P

For the remaining five years (15 years total - 4 years - 6 years = 5 years), the simple interest is calculated at the rate of 12% per annum. So, the interest for the remaining five years = P * 12% * 5 = 0.12P * 5 = 0.6P

The total interest paid by Imran is given as Rs. 12,160.

So, adding up the interest for each period:

Total interest = 0.32P + 0.6P + 0.6P = 1.52P

Given that the total interest is Rs. 12,160, we can set up the equation:

1.52P = 12,160

Now, solve for P:

P = 12,160 / 1.52 P = 8,000

Therefore, Imran borrowed Rs. 8,000.


Q :  

The cost price of a book is ₹110 and the selling price is ₹123.20. What percent profit will the bookseller make on selling it?

(A) 11%

(B) 12%

(C) 13%

(D) 14%

Correct Answer : B
Explanation :

To calculate the percentage profit made by the bookseller, we use the formula:

Profit Percentage=(Selling Price−Cost PriceCost Price)×100%Profit Percentage=(Cost PriceSelling Price−Cost Price)×100%

Given: Cost Price (𝐶𝑃CP) = ₹110
Selling Price (𝑆𝑃SP) = ₹123.20

Using the formula:

Profit Percentage=(123.20−110110)×100%Profit Percentage=(110123.20−110)×100%

Profit Percentage=(13.20110)×100%Profit Percentage=(11013.20)×100%

Profit Percentage=(0.12)×100%Profit Percentage=(0.12)×100%

Profit Percentage=12%Profit Percentage=12%

So, the bookseller will make a profit of 12%.


Q :  

A fruit seller bought bananas at the rate of 6 for ₹ 15 and sold them at the rate of 4 for ₹ 12, find his profit or loss percentage.

(A) 17%

(B) 19%

(C) 20%

(D) 22%

Correct Answer : C
Explanation :

To find the profit or loss percentage, we first need to calculate the cost price (CP) and the selling price (SP) of the bananas.

Given: Cost price of 6 bananas = ₹ 15 So, cost price of 1 banana = ₹ 15 / 6 = ₹ 2.50

Now, let's calculate the selling price: Selling price of 4 bananas = ₹ 12 So, selling price of 1 banana = ₹ 12 / 4 = ₹ 3.00

Now, we can compare the CP and SP to determine the profit or loss.

If SP > CP, it's a profit. If SP < CP, it's a loss.

Here, CP = ₹ 2.50 SP = ₹ 3.00

So, it's a profit of ₹ 0.50 per banana.

To find the profit percentage: Profit per banana / CP per banana * 100%

Profit per banana = ₹ 3.00 - ₹ 2.50 = ₹ 0.50

Profit percentage = (0.50 / 2.50) * 100% = 20%

Therefore, the fruit seller made a profit of 20%.


Q :  

The sum of weights of A and B is 80 kg. 50% of A's weight is times the weight of B. Find the difference between their weights. 

(A) 20 kg

(B) 10 kg

(C) 25 kg

(D) 15 kg

Correct Answer : A
Explanation :

Let's denote the weight of A as 𝑥x kg and the weight of B as 𝑦y kg.

Given:

  1. 𝑥+𝑦=80x+y=80 (Sum of weights of A and B is 80 kg)
  2. 0.5𝑥=56𝑦0.5x=65y (50% of A's weight is 5665 times the weight of B)

We can solve these two equations to find the values of 𝑥x and 𝑦y, and then calculate the difference between their weights.

From equation 2: 0.5𝑥=56𝑦0.5x=65y Multiply both sides by 2 to get rid of the fraction: 𝑥=56𝑦×2x=65y×2 𝑥=106𝑦x=610y 𝑥=53𝑦x=35y

Now substitute this expression for 𝑥x into equation 1: 53𝑦+𝑦=8035y+y=80 83𝑦=8038y=80 Multiply both sides by 3883: 𝑦=80×38y=80×83 𝑦=30y=30

Now that we have found the weight of B, we can find the weight of A using equation 1: 𝑥+30=80x+30=80 𝑥=80−30x=80−30 𝑥=50x=50

So, the weight of A is 50 kg and the weight of B is 30 kg.

Now, let's find the difference between their weights: Difference=Weight of A−Weight of BDifference=Weight of A−Weight of B Difference=50−30Difference=50−30 Difference=20Difference=20

Therefore, the difference between their weights is 20 kg.


Q :  

In an examination, 92% of the students passed and 480 students failed. If so, how many students appeared in the examination?

(A) 5800

(B) 6200

(C) 6000

(D) 5000

Correct Answer : C
Explanation :

Let's denote the total number of students who appeared in the examination as 𝑥x.

Given that 92% of the students passed, it means 8% failed because the total percentage is 100%.

We can set up the equation:

8% of 𝑥=4808% of x=480

To find 8% of 𝑥x, we multiply 𝑥x by 81001008 (which is the same as multiplying by 0.08):

0.08𝑥=4800.08x=480

Now, we can solve for 𝑥x:

𝑥=4800.08x=0.08480𝑥=6000x=6000

So, 6000 students appeared in the examination.



Q :  

The price of sugar increases by 15%. By what percentage should the consumption of sugar be decreased so that the expenditure on the purchase of sugar remains the same? [Give your answer correct to 2 decimal places.]

(A) 11.11%

(B) 12.5%

(C) 14.16%

(D) 13.04%

Correct Answer : D
Explanation :

To solve this problem, let's denote:

  • Initial price of sugar = P
  • Initial quantity consumed = Q
  • Initial expenditure = PQ

After the price increases by 15%, the new price becomes 1.15P.

To keep the expenditure constant, the new quantity consumed (let's call it Q') can be calculated using the formula:

New expenditure = New price × New quantity

Setting the new expenditure equal to the initial expenditure:

PQ = (1.15P) * Q'

Now, solve for Q':

Q' = PQ / (1.15P)

Simplify:

Q' = Q / 1.15

Now, let's find the percentage decrease in consumption:

Percentage decrease = [(Q - Q') / Q] * 100

Substituting the value of Q':

Percentage decrease = [(Q - (Q / 1.15)) / Q] * 100

Percentage decrease = [(Q * (1 - 1/1.15)) / Q] * 100

Percentage decrease ≈ [(1 - 0.8696) * 100] ≈ 13.04%

Therefore, the consumption of sugar should be decreased by approximately 13.04% to keep the expenditure on the purchase of sugar the same after a 15% increase in price.


Q :  

If the population of a town is 12.000 and the population increases at the rate of 10% per annum, then find the population. after 3 years.

(A) 15,972

(B) 12,200

(C) 11,200

(D) 10,200

Correct Answer : A
Explanation :

To find the population after 3 years given that it increases at a rate of 10% per annum, you can use the formula for exponential growth:

𝑃=𝑃0×(1+𝑟)𝑛P=P0×(1+r)n

Where:

  • 𝑃P = Population after 𝑛n years
  • 𝑃0P0 = Initial population
  • 𝑟r = Rate of increase (in decimal form)
  • 𝑛n = Number of years

Given:

  • 𝑃0=12,000P0=12,000 (Initial population)
  • 𝑟=0.10r=0.10 (10% increase per annum)
  • 𝑛=3n=3 (Number of years)

Substitute these values into the formula:

𝑃=12,000×(1+0.10)3P=12,000×(1+0.10)3

𝑃=12,000×(1.10)3P=12,000×(1.10)3

𝑃=12,000×(1.331)P=12,000×(1.331)

𝑃=15,972P=15,972

So, the population after 3 years would be approximately 15,972.



Related categories

Very important related articles. Read now

The Most Comprehensive Exam Preparation Platform

Get the Examsbook Prep App Today