Quantitative Aptitude Practice Set 1 - Basic Problems

🎯 Practice Overview

This practice set focuses on fundamental quantitative aptitude concepts that frequently appear in IBPS PO exams. Each question includes detailed step-by-step solutions.

📊 Practice Questions

Question 1: Percentage Problem

Question: A student scored 75% marks in an exam. If the total marks are 800, how many marks did the student score?

Options: A) 500 B) 600 C) 650 D) 700 E) 750

Solution:

Marks scored = 75% of 800
= (75/100) × 800
= 0.75 × 800
= 600 marks

Answer: B) 600

Explanation: 75% means 75 out of 100, so we multiply 800 by 0.75.

Question 2: Ratio Problem

Question: The ratio of A’s salary to B’s salary is 3:4. If B’s salary is ₹48,000, what is A’s salary?

Options: A) ₹36,000 B) ₹30,000 C) ₹40,000 D) ₹45,000 E) ₹50,000

Solution:

Let A's salary = 3x, B's salary = 4x
Given: 4x = 48,000
x = 48,000 ÷ 4 = 12,000
A's salary = 3x = 3 × 12,000 = 36,000

Answer: A) ₹36,000

Explanation: In a 3:4 ratio, if one part is 4x = 48,000, then x = 12,000 and A’s salary = 3x.

Question 3: Simple Interest

Question: Simple interest on a sum of ₹15,000 for 2 years at 8% per annum is:

Options: A) ₹2,400 B) ₹2,600 C) ₹2,800 D) ₹3,000 E) ₹3,200

Solution:

Simple Interest = (P × R × T) / 100
= (15,000 × 8 × 2) / 100
= (240,000) / 100
= ₹2,400

Answer: A) ₹2,400

Explanation: SI = (Principal × Rate × Time) ÷ 100

Question 4: Average Problem

Question: The average of 5 numbers is 12. If one number is excluded, the average becomes 10. What is the excluded number?

Options: A) 18 B) 20 C) 22 D) 24 E) 30

Solution:

Sum of 5 numbers = Average × Count = 12 × 5 = 60
Sum of remaining 4 numbers = 10 × 4 = 40
Excluded number = 60 - 40 = 20

Answer: B) 20

Explanation: When we exclude one number, the sum decreases by that number.

Question 5: Profit and Loss

Question: A shopkeeper bought an article for ₹80 and sold it for ₹100. His profit percentage is:

Options: A) 20% B) 25% C) 30% D) 40% E) 50%

Solution:

Cost Price = ₹80
Selling Price = ₹100
Profit = SP - CP = 100 - 80 = ₹20
Profit % = (Profit / CP) × 100
= (20 / 80) × 100 = 25%

Answer: B) 25%

Explanation: Profit % is always calculated on cost price.

Question 6: Time and Work

Question: A can complete a work in 12 days and B can complete it in 18 days. Working together, how many days will they take to complete the work?

Options: A) 6 days B) 7.2 days C) 8 days D) 9 days E) 10 days

Solution:

A's one day work = 1/12
B's one day work = 1/18
Together one day work = 1/12 + 1/18
= (3/36 + 2/36) = 5/36
Time taken = 36/5 = 7.2 days

Answer: B) 7.2 days

Explanation: Work = Rate × Time, so Time = Work ÷ Rate

Question 7: Number System

**Question: Which of the following is a prime number?

Options: A) 21 B) 33 C) 37 D) 51 E) 77

Solution:

21 = 3 × 7 (not prime)
33 = 3 × 11 (not prime)
37 = prime (only divisible by 1 and 37)
51 = 3 × 17 (not prime)
77 = 7 × 11 (not prime)

Answer: C) 37

Explanation: Prime numbers have exactly two factors (1 and itself).

Question 8: Square Root

**Question: √�625 = ?

Options: A) 15 B) 20 C) 25 D) 30 E) 35

Solution:

√�625 = √�(25 × 25) = 25

Answer: C) 25

Explanation: 25 × 25 = 625, so square root is 25.

Question 9: Age Problem

Question: Father is twice as old as his son. 10 years ago, father was 3 times as old as his son. What is the current age of father?

Options: A) 30 years B) 40 years C) 50 years D) 60 years E) 70 years

Solution:

Let current ages be: Son = x, Father = 2x
10 years ago: Son = x - 10, Father = 2x - 10
Given: 2x - 10 = 3(x - 10)
2x - 10 = 3x - 30
-x = -20, so x = 20
Father's current age = 2x = 40 years

Answer: B) 40 years

Explanation: Age difference remains constant, so we set up equation based on given condition.

Question 10: Discount Problem

Question: A shirt marked at ₹500 is sold at 20% discount. What is the selling price?

Options: A) ₹300 B) ₹350 C) ₹400 D) ₹450 E) ₹475

Solution:

Discount = 20% of ₹500 = ₹100
Selling Price = Marked Price - Discount = 500 - 100 = ₹400

Answer: C) ₹400

Explanation: Discount is always calculated on marked price.

📊 Performance Analysis

Score Distribution:

• Easy Questions (1-6): Focus on basic concepts
• Medium Questions (7-8): Require multiple steps
• Hard Questions (9-10): More complex calculations

Common Mistakes to Avoid:

1. Percentage: Using wrong base for calculation
2. Ratio: Mixing up the ratio terms
3. Simple Interest: Forgetting to divide by 100
4. Average: Not calculating sum first
5. Profit: Using SP as base instead of CP
6. Time and Work: Adding time periods directly
7. Prime Numbers: Not checking divisibility
8. Square Roots: Not recognizing perfect squares
9. Age Problems: Setting up wrong equations
10. Discount: Calculating on SP instead of MP

Time Management Tips:

• Easy questions: 30-45 seconds each
• Medium questions: 60-90 seconds each
• Hard questions: 2-3 minutes maximum
• Total time: Aim for 8-10 minutes

🎯 Next Steps

Practice Strategy:

1. Master basic formulas - Memorize key formulas
2. Improve calculation speed - Practice mental math
3. Understand concepts - Don’t just memorize
4. Regular practice - Daily 10-15 questions
5. Review mistakes - Learn from errors

Recommended Study Plan:

• Daily: 1 practice set (10 questions)
• Weekly: Review all topics covered
• Monthly: Full mock test practice
• Before exam: Focus on weak areas

🔗 Related Topics

• - Percentage problems
• - Ratio and proportion
• - Simple interest
• - Average calculations
• - Profit and loss

📚� Continue Learning

Master these concepts:

1. Practice with more complex problems
2. Learn shortcut techniques
3. Take timed practice tests
4. Review and improve your performance