Here are 25 multiple-choice questions on Basic Numerical Ability, suitable for JKSSB and similar competitive exams, with answers and explanations:
Q1. What is the value of 5 + 3 × (4 – 2)?
(a) 16
(b) 11
(c) 8
(d) 10
Answer: (b)
Explanation: According to the order of operations (BODMAS/PEMDAS), solve the parenthesis first: 4 – 2 = 2. Then perform multiplication: 3 × 2 = 6. Finally, perform addition: 5 + 6 = 11.
Q2. Simplify: 15 / 3 × 2 + 7 – 1.
(a) 16
(b) 15
(c) 14
(d) 10
Answer: (a)
Explanation: Follow BODMAS/PEMDAS. Division: 15 / 3 = 5. Multiplication: 5 × 2 = 10. Then addition and subtraction from left to right: 10 + 7 = 17, then 17 – 1 = 16.
Q3. What is 25% of 200?
(a) 25
(b) 50
(c) 75
(d) 100
Answer: (b)
Explanation: To find 25% of 200, convert 25% to a decimal (0.25) or a fraction (1/4). Then multiply: 0.25 × 200 = 50, or (1/4) × 200 = 50.
Q4. If a jacket costing ₹800 is sold at a 10% discount, what is its selling price?
(a) ₹720
(b) ₹700
(c) ₹880
(d) ₹750
Answer: (a)
Explanation: Discount amount = 10% of ₹800 = (10/100) × 800 = ₹80. Selling Price = Original Price – Discount = ₹800 – ₹80 = ₹720.
Q5. A car travels at a speed of 60 km/h. How much distance will it cover in 2.5 hours?
(a) 120 km
(b) 150 km
(c) 180 km
(d) 200 km
Answer: (b)
Explanation: Distance = Speed × Time. Distance = 60 km/h × 2.5 h = 150 km.
Q6. What is the average of the numbers 12, 18, 24, and 30?
(a) 20
(b) 21
(c) 22
(d) 23
Answer: (b)
Explanation: Average = Sum of numbers / Count of numbers. Sum = 12 + 18 + 24 + 30 = 84. Count = 4. Average = 84 / 4 = 21.
Q7. If 3 dozen eggs cost ₹108, what is the cost of 1 egg?
(a) ₹2
(b) ₹3
(c) ₹4
(d) ₹5
Answer: (b)
Explanation: 1 dozen = 12 eggs. So, 3 dozen = 3 × 12 = 36 eggs. Cost of 1 egg = Total cost / Number of eggs = ₹108 / 36 = ₹3.
Q8. Convert 0.75 into a fraction in its simplest form.
(a) 3/4
(b) 75/100
(c) 1/2
(d) 3/5
Answer: (a)
Explanation: 0.75 can be written as 75/100. To simplify, divide both numerator and denominator by their greatest common divisor, which is 25. 75 ÷ 25 = 3 and 100 ÷ 25 = 4. So, 3/4.
Q9. Which of the following is the smallest fraction?
(a) 1/2
(b) 3/4
(c) 2/3
(d) 5/8
Answer: (d)
Explanation: To compare, convert them to equivalent fractions with a common denominator (LCM of 2, 4, 3, 8 is 24) or to decimals:
1/2 = 0.5
3/4 = 0.75
2/3 ≈ 0.667
5/8 = 0.625
Comparing the decimals, 0.5 is the smallest, but 5/8 (0.625) is the smallest among the given options if 1/2 wasn’t provided. Let’s re-evaluate.
1/2=0.5
3/4=0.75
2/3=0.66
5/8=0.625
Error in my solution. The smallest is 1/2.
Let’s fix the question or options. Assuming a common type of error in exam questions: if the intent was for 5/8 to be smallest among typical options.
Let’s choose another set of options to make 5/8 plausible.
Let options be:
(a) 4/5 = 0.8
(b) 7/10 = 0.7
(c) 2/3 = 0.66
(d) 5/8 = 0.625
Answer: (d)
Explanation: Convert to decimals for easy comparison: 4/5 = 0.8, 7/10 = 0.7, 2/3 ≈ 0.667, 5/8 = 0.625. The smallest is 0.625, which corresponds to 5/8.
Q10. Calculate the simple interest on ₹5000 at 6% per annum for 3 years.
(a) ₹900
(b) ₹600
(c) ₹1000
(d) ₹800
Answer: (a)
Explanation: Simple Interest (SI) = (Principal × Rate × Time) / 100.
SI = (5000 × 6 × 3) / 100 = 90000 / 100 = ₹900.
Q11. What is the sum of the first 10 natural numbers?
(a) 45
(b) 50
(c) 55
(d) 60
Answer: (c)
Explanation: The sum of the first ‘n’ natural numbers is given by the formula n(n+1)/2. For n=10, sum = 10(10+1)/2 = 10 × 11 / 2 = 110 / 2 = 55.
Q12. If A can do a piece of work in 10 days and B can do the same work in 15 days, how many days will they take to complete it together?
(a) 5 days
(b) 6 days
(c) 7 days
(d) 8 days
Answer: (b)
Explanation: A’s 1-day work = 1/10. B’s 1-day work = 1/15.
Together, their 1-day work = 1/10 + 1/15 = (3 + 2) / 30 = 5/30 = 1/6.
So, they will take 6 days to complete the work together.
Q13. The ratio of two numbers is 3:5. If their sum is 80, what is the larger number?
(a) 30
(b) 40
(c) 50
(d) 60
Answer: (c)
Explanation: Let the numbers be 3x and 5x. Their sum is 3x + 5x = 8x.
Given sum = 80, so 8x = 80, which means x = 10.
The larger number is 5x = 5 × 10 = 50.
Q14. Find the value of (2^3 × 3^2) / 6.
(a) 6
(b) 12
(c) 18
(d) 24
Answer: (b)
Explanation: 2^3 = 2 × 2 × 2 = 8. 3^2 = 3 × 3 = 9.
So, (8 × 9) / 6 = 72 / 6 = 12.
Q15. What is the least common multiple (LCM) of 4, 6, and 8?
(a) 12
(b) 16
(c) 24
(d) 36
Answer: (c)
Explanation: Multiples of 4: 4, 8, 12, 16, 20, 24, …
Multiples of 6: 6, 12, 18, 24, 30, …
Multiples of 8: 8, 16, 24, 32, …
The smallest common multiple is 24.
Q16. Find the greatest common divisor (GCD) or highest common factor (HCF) of 18, 24, and 30.
(a) 3
(b) 6
(c) 9
(d) 12
Answer: (b)
Explanation: Factors of 18: 1, 2, 3, 6, 9, 18
Factors of 24: 1, 2, 3, 4, 6, 8, 12, 24
Factors of 30: 1, 2, 3, 5, 6, 10, 15, 30
The greatest common factor is 6.
Q17. A shopkeeper buys an item for ₹500 and sells it for ₹650. What is his profit percentage?
(a) 20%
(b) 25%
(c) 30%
(d) 35%
Answer: (c)
Explanation: Profit = Selling Price – Cost Price = ₹650 – ₹500 = ₹150.
Profit Percentage = (Profit / Cost Price) × 100 = (150 / 500) × 100 = (3/10) × 100 = 30%.
Q18. If 30% of a number is 150, what is the number?
(a) 400
(b) 500
(c) 450
(d) 600
Answer: (b)
Explanation: Let the number be x.
30% of x = 150
(30/100) × x = 150
0.3x = 150
x = 150 / 0.3 = 1500 / 3 = 500.
Q19. What is the value of √144 + √81?
(a) 21
(b) 20
(c) 22
(d) 19
Answer: (a)
Explanation: √144 = 12 (since 12 × 12 = 144).
√81 = 9 (since 9 × 9 = 81).
So, 12 + 9 = 21.
Q20. A sum of money doubles itself in 5 years at simple interest. What is the rate of interest per annum?
(a) 10%
(b) 15%
(c) 20%
(d) 25%
Answer: (c)
Explanation: If the sum doubles, the interest earned is equal to the principal (P).
SI = P. Time (T) = 5 years.
SI = (P × R × T) / 100
P = (P × R × 5) / 100
1 = (R × 5) / 100
100 = 5R
R = 100 / 5 = 20%.
Q21. How many seconds are there in 2 hours?
(a) 120
(b) 3600
(c) 7200
(d) 1200
Answer: (c)
Explanation: 1 hour = 60 minutes.
1 minute = 60 seconds.
So, 1 hour = 60 × 60 = 3600 seconds.
2 hours = 2 × 3600 = 7200 seconds.
Q22. Round off 345.678 to two decimal places.
(a) 345.67
(b) 345.68
(c) 345.70
(d) 346.00
Answer: (b)
Explanation: To round to two decimal places, look at the third decimal place. If it is 5 or greater, round up the second decimal place. Here, the third decimal place is 8 (which is ≥ 5), so round up the second decimal place (7 becomes 8). Thus, 345.68.
Q23. What is the value of 0.2 × 0.3 × 0.4?
(a) 0.024
(b) 0.24
(c) 0.0024
(d) 2.4
Answer: (a)
Explanation: Multiply the numbers without decimals first: 2 × 3 × 4 = 24.
Then count the total number of decimal places in the original numbers (1 + 1 + 1 = 3).
Place the decimal point 3 places from the right in the product: 0.024.
Q24. If the perimeter of a square is 36 cm, what is its area?
(a) 18 cm²
(b) 36 cm²
(c) 81 cm²
(d) 108 cm²
Answer: (c)
Explanation: The perimeter of a square = 4 × side.
Given perimeter = 36 cm, so 4 × side = 36 cm.
Side = 36 / 4 = 9 cm.
Area of a square = side × side = 9 cm × 9 cm = 81 cm².
Q25. A mixture contains milk and water in the ratio 4:1. If there are 20 litres of milk, what is the total quantity of the mixture?
(a) 20 litres
(b) 25 litres
(c) 16 litres
(d) 5 litres
Answer: (b)
Explanation: The ratio of milk to water is 4:1. This means for every 4 parts of milk, there is 1 part of water.
If 4 parts represent 20 litres of milk, then 1 part = 20 / 4 = 5 litres.
The total parts in the mixture = 4 (milk) + 1 (water) = 5 parts.
Total quantity of mixture = 5 parts × 5 litres/part = 25 litres.
