Question 1

1. What is the sum of the first 20 natural numbers?

A) 200B) 210C) 220D) 190

Answer

✓ Correct Answer: Option B

Explanation: Solution: The sum of first n natural numbers is given by $\frac{n(n+1)}{2}$. Here n = 20, so Sum = $\frac{20 \times 21}{2} = 10 \times 21 = 210$.

Question 2

2. Which of the following is the smallest prime number?

A) 0B) 1C) 2D) 3

Question 3

3. What is the unit digit in the product $23 \times 45 \times 67$?

A) 5B) 0C) 3D) 7

Answer

✓ Correct Answer: Option A

Explanation: Solution: Multiply the unit digits: $3 \times 5 \times 7$. $3 \times 5 = 15$ (Unit digit 5). $5 \times 7 = 35$ (Unit digit 5). The final unit digit is 5.

Question 4

4. Find the difference between the place value and face value of 5 in the number 156?

A) 50B) 5C) 0D) 45

Answer

✓ Correct Answer: Option D

Explanation: Solution: Place value of 5 in 156 is $5 \times 10 = 50$. Face value of 5 is 5. Difference = 50 - 5 = 45.

Question 5

5. Find the LCM of 4 and 6.

A) 2B) 24C) 12D) 10

Answer

✓ Correct Answer: Option C

Explanation: Solution: Multiples of 4: 4, 8, 12, 16... Multiples of 6: 6, 12, 18... The Least Common Multiple is 12.

Question 6

6. Find the HCF of 12 and 16.

A) 4B) 2C) 8D) 48

Answer

✓ Correct Answer: Option A

Explanation: Solution: Factors of 12: 1, 2, 3, 4, 6, 12. Factors of 16: 1, 2, 4, 8, 16. Common factors: 1, 2, 4. The Highest Common Factor is 4.

Question 7

7. If the HCF of two numbers 10 and 15 is 5, what is their LCM?

A) 150B) 30C) 25D) 60

Answer

✓ Correct Answer: Option B

Explanation: Solution: We know that $HCF \times LCM = Product of numbers$. $5 \times LCM = 10 \times 15 = 150$. LCM = 150 / 5 = 30.

Question 8

8. What is the HCF of two distinct prime numbers p and q?

A) 0B) 1C) pqD) p+q

Answer

✓ Correct Answer: Option B

Explanation: Solution: Prime numbers have only two factors: 1 and themselves. Since p and q are distinct, their only common factor is 1. Thus, HCF is 1.

Question 9

9. Simplify: 25 - [20 - \{10 - (7 - 5)\}]

A) 10B) 15C) 13D) 17

Answer

✓ Correct Answer: Option C

Explanation: Solution: Using VBODMAS rule: 25 - [20 - \{10 - 2\}] 25 - [20 - 8] 25 - 12 = 13.

Question 10

10. Evaluate: $\sqrt{144} + \sqrt{81}$

A) 20B) 15C) 25D) 21

Answer

✓ Correct Answer: Option D

Explanation: Solution: $\sqrt{144} = 12$ and $\sqrt{81} = 9$. 12 + 9 = 21.

Question 11

11. What is the value of $0.5 \times 0.2$?

A) 0.1B) 1.0C) 0.01D) 0.11

Answer

✓ Correct Answer: Option A

Explanation: Solution: $0.5 \times 0.2 = \frac{5}{10} \times \frac{2}{10} = \frac{10}{100} = 0.1$.

Question 12

12. Solve: $(2 + 3)^2$

A) 13B) 25C) 10D) 15

Answer

✓ Correct Answer: Option B

Question 13

13. What is 15% of 200?

A) 20B) 25C) 30D) 35

Answer

✓ Correct Answer: Option C

Question 14

14. Convert the fraction $\frac{2}{5}$ into a percentage.

A) 40%B) 20%C) 50%D) 60%

Answer

✓ Correct Answer: Option A

Explanation: Solution: To convert a fraction to percentage, multiply by 100. $\frac{2}{5} \times 100 = 2 \times 20 = 40%$.

Question 15

15. If a number increases from 50 to 60, find the percentage increase.

A) 10%B) 20%C) 25%D) 15%

Answer

✓ Correct Answer: Option B

Explanation: Solution: Increase = 60 - 50 = 10. Percentage Increase = $\frac{Increase}{Original Value} \times 100 = \frac{10}{50} \times 100 = 20%$.

Question 16

16. x is 25% of 80. What is the value of x?

A) 10B) 15C) 25D) 20

Answer

✓ Correct Answer: Option D

Explanation: Solution: $x = \frac{25}{100} \times 80 = \frac{1}{4} \times 80 = 20$.

Question 17

17. If Cost Price (CP) = 400 and Selling Price (SP) = 440, find the Profit Percentage.

A) 5%B) 10%C) 15%D) 40%

Answer

✓ Correct Answer: Option B

Explanation: Solution: Profit = 440 - 400 = 40. Profit % = $\frac{Profit}{CP} \times 100 = \frac{40}{400} \times 100 = 10%$.

Question 18

18. A man buys a table for 500 and sells it at a loss of 5%. What is the Selling Price?

A) 450B) 480C) 475D) 495

Answer

✓ Correct Answer: Option C

Explanation: Solution: Loss = 5% of 500 = $\frac{5}{100} \times 500 = 25$. SP = CP - Loss = 500 - 25 = 475.

Question 19

19. A toy bought for 200 is sold for 150. Calculate the loss amount.

A) 50B) 25C) 30D) 100

Answer

✓ Correct Answer: Option A

Question 20

20. If SP = 110 and Profit = 10, what is the Cost Price?

A) 120B) 110C) 105D) 100

Answer

✓ Correct Answer: Option D

Quantitative Aptitude Mix (Set 1) Quiz - Number System, HCF/LCM, Profit/Loss

1. What is the sum of the first 20 natural numbers?

2. Which of the following is the smallest prime number?

3. What is the unit digit in the product $23 \times 45 \times 67$?

4. Find the difference between the place value and face value of 5 in the number 156?

5. Find the LCM of 4 and 6.

6. Find the HCF of 12 and 16.

7. If the HCF of two numbers 10 and 15 is 5, what is their LCM?

8. What is the HCF of two distinct prime numbers p and q?

9. Simplify: 25 - [20 - \{10 - (7 - 5)\}]

10. Evaluate: $\sqrt{144} + \sqrt{81}$

11. What is the value of $0.5 \times 0.2$?

12. Solve: $(2 + 3)^2$

13. What is 15% of 200?

14. Convert the fraction $\frac{2}{5}$ into a percentage.

15. If a number increases from 50 to 60, find the percentage increase.

16. x is 25% of 80. What is the value of x?

17. If Cost Price (CP) = 400 and Selling Price (SP) = 440, find the Profit Percentage.

18. A man buys a table for 500 and sells it at a loss of 5%. What is the Selling Price?

19. A toy bought for 200 is sold for 150. Calculate the loss amount.

20. If SP = 110 and Profit = 10, what is the Cost Price?