IOCL 2025 aptitude
Quantitative, reasoning, and verbal drills with solutions
IOCL Placement Papers 2025
Overview
This page collects IOCL placement papers from 2025 with practice questions, worked solutions, and the exam pattern students reported that cycle. Use it when you want drive history: what the first round looked like, which topics repeated, and how to approach solutions. Work the sets below under a timer, then compare with newer material so your prep matches both established IOCL patterns and recent shifts.
Download / jump links
IOCL 2025 coding
DSA practice aligned to IOCL online assessments
IOCL interview experience
Round structure and tips from student reports
IOCL prep guide
Study plan and weekly schedule
IOCL Aptitude Mock Quiz
Timed placement-style MCQs with score and explanations after you submit. Use it to check speed and accuracy before the real test.
Questions15
Time10 min
Quantitative
Reading Comprehension (2024 - Real Question)
According to the passage, a major consequence was a significant increase in urban populations due to migration for work opportunities.
Verbal
Problem: Choose the correct sentence: a) Neither the students nor the teacher were present b) Neither the students nor the teacher was present c) Neither the students or the teacher was present
With "neither...nor", the verb agrees with the subject closer to it. "Teacher" is singular, so "was" is correct.
Quantitative
Find the error: "Each of the students have completed their assignment."
"Each" is singular, so "has" should be used instead of "have", and "his or her" instead of "their".
Verbal
Choose correctly spelled word:
Correct spelling is Necessary.
Quantitative
A and B invest ₹5,000 and ₹7,000 respectively in a business. After 6 months, A withdraws ₹2,000. If the profit at the end of the year is ₹4,500, find B's share.
A's investment: 5000 × 6 + 3000 × 6 = 30,000 + 18,000 = 48,000 B's investment: 7000 × 12 = 84,000 Ratio = 48,000 : 84,000 = 4 : 7 B's share = 7/(4+7) × 4500 = 7/11 × 4500 = ₹2,863.64
Reasoning
Statements: 1) Some boxes are cars, 2) Some cars are roads Conclusions: I) Some roads are boxes, II) Some cars are boxes, III) No box is a road, IV) Some roads are cars.
Correct answer: Only II and IV follow
Reasoning
Find the next number: 1, 3, 6, 10, 15, ?
Correct answer: 21
Verbal
A person who speaks many languages is a:
Polyglot speaks several languages.
Reasoning
A walks 10m North, turns right walks 5m, turns right walks 10m. Direction from start?
Correct answer: East (5m east of starting point)
Quantitative
A 120 m train crosses a pole in 8 s. Speed in km/h is:
Speed = 120/8 = 15 m/s = 54 km/h.
Reasoning
Number Series - 37, 47, 58, ?, 79, 95
Correct answer: 70
Verbal
He _____ to school every day.
Singular present.
Quantitative
A number is first increased by 25% and then decreased by 20%. Find the net percentage change.
Let number = 100 After 25% increase: 100 + 25 = 125 After 20% decrease: 125 - 20% of 125 = 125 - 25 = 100 Net change = 0%
Reasoning
Find the next number: 5, 10, 20, 40, ?
×2 each → 80.
Quantitative
The ratio of the ages of two persons is 4:3. After 6 years, the ratio becomes 9:7. What are their present ages?
Let present ages be 4x and 3x After 6 years: (4x + 6)/(3x + 6) = 9/7 7(4x + 6) = 9(3x + 6) 28x + 42 = 27x + 54 x = 12 Present ages: 4×12 = 48 years, 3×12 = 36 years
Your score
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Review
IOCL exam pattern 2025
| Section | What shows up | Prep focus |
|---|---|---|
| Technical / domain | Syllabus aligned to the notification | Topic checklist |
| Aptitude | Quant + reasoning | Speed with accuracy |
| Interview | Subject depth + projects | Clear fundamentals |
First round: IOCL GATE-based Recruitment
Skills emphasized: GATE technical, GD/Interview
Languages: N/A for core
Sample IOCL questions with solutions
These are practice-style questions aligned to patterns students report for IOCL drives around 2025. They are not leaked live papers. Work them timed, then read the solutions only after you have an answer.
Quantitative aptitude (2025)
Q1: Distance from speed
Problem: A vehicle travels at 60 km/h for 2.5 hours. How far does it go?
Solution: Distance = speed × time = 60 × 2.5 = 150 km.
Answer: 150 km
Q2: Compound ratio
Problem: If two ratios are 3:5 and 5:7, what is the compound ratio?
Solution: Compound ratio = (3/5) × (5/7) = 3/7, written as 3:7.
Answer: 3:7
Q3: SI three years
Problem: Find simple interest on ₹5000 at 8% per annum for 3 years.
Solution: SI = 5000 × 8 × 3 / 100 = ₹1200.
Answer: ₹1200
Q4: Boat upstream
Problem: A boat’s speed in still water is 15 km/h and the stream is 3 km/h. How long to cover 36 km upstream?
Solution: Upstream speed = 15 − 3 = 12 km/h. Time = 36 / 12 = 3 hours.
Answer: 3 hours
Q5: Mixture milk
Problem: A mixture has milk and water in the ratio 4:1. If 5 litres of water are added to 20 litres of mixture, what is the new milk:water ratio?
Solution: In 20 L: milk = 16 L, water = 4 L. After adding 5 L water: milk 16, water 9. Ratio = 16:9.
Answer: 16:9
Q6: CI vs SI hint
Problem: Find compound interest on ₹10,000 at 10% per annum for 2 years, compounded annually.
Solution: Amount = 10000 × (1.1)² = 10000 × 1.21 = ₹12,100. CI = 12100 − 10000 = ₹2100. (SI for same period would be ₹2000; the extra ₹100 is interest on first-year interest.)
Answer: ₹2100
Q7: Clock angle
Problem: What is the angle between the hour and minute hands at 3:00?
Solution: At 3:00 the hands are exactly 90° apart (one quarter of the circle).
Answer: 90°
Q8: Permutation basic
Problem: In how many ways can 5 different books be arranged on a shelf?
Solution: Arrangements of 5 distinct items = 5! = 120.
Answer: 120
Logical reasoning (2025)
Q1: Seating hint
Problem: Five friends sit in a row. A is to the left of B but right of C. D is to the right of B and left of E. Who is in the middle?
Solution: Order from left to right: C, A, B, D, E. The middle seat is B.
Answer: B
Q2: Analogy
Problem: Book is to Reading as Fork is to ?
Solution: A book is used for reading; a fork is used for eating.
Answer: Eating
Q3: Odd one out
Problem: Find the odd one out: 3, 5, 7, 9, 11
Solution: 3, 5, 7, and 11 are prime. 9 = 3×3 is composite, so it is the odd one out.
Answer: 9
Q4: Coding letter shift
Problem: If CAT is coded as DBU, how is DOG coded in the same way?
Solution: Each letter moves +1 in the alphabet: C→D, A→B, T→U. D→E, O→P, G→H → EPH.
Answer: EPH
Coding practice (2025)
Coding Q1: Stack with min
Problem: Design a stack that supports push, pop, top, and getMin in average O(1) time.
Approach: Keep a parallel min-stack (or store pairs). When pushing, also push the new minimum. When popping, pop both stacks.
Complexity: O(1) per operation amortized
IOCL tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Coding Q2: Maximum subarray sum (Kadane)
Problem: Given an integer array, find the contiguous subarray with the largest sum and return that sum. Example: [-2,1,-3,4,-1,2,1,-5,4] → 6 (from [4,-1,2,1]).
Approach: Keep a running sum. If the running sum drops below 0, reset it to 0 before taking the next element (or track the best ending-here value). Track the global maximum as you scan once from left to right.
Complexity: O(n) time, O(1) extra space
IOCL tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Coding Q3: Reverse a string in place
Problem: Given a mutable character array representing a string, reverse it in place without allocating another array of the same size.
Approach: Use two pointers at the start and end. Swap characters, then move inward until the pointers meet. Watch empty and single-character inputs.
Complexity: O(n) time, O(1) extra space
IOCL tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Coding Q4: Check prime
Problem: Write a function that returns true if n is prime and false otherwise. Handle n < 2 correctly.
Approach: Return false for n < 2. Trial-divide from 2 to floor(sqrt(n)). If any divisor divides n evenly, it is composite; otherwise prime.
Complexity: O(√n) time
IOCL tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Coding Q5: Valid parentheses
Problem: Given a string containing only ‘()[]’, decide whether the brackets are balanced and correctly nested.
Approach: Scan left to right with a stack. Push opening brackets. On a closing bracket, the stack top must be the matching opener. At the end the stack must be empty.
Complexity: O(n) time, O(n) space
IOCL tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Coding Q6: Two Sum
Problem: Given an array of integers and a target, return indices of two numbers that add up to the target. Assume exactly one solution and you may not use the same element twice.
Approach: Walk the array once. For each value x, check whether target − x was seen earlier in a hash map of value → index. If yes, return both indices; else store x.
Complexity: O(n) time, O(n) space
IOCL tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Coding Q7: Longest substring without repeating characters
Problem: Given a string s, find the length of the longest substring without repeating characters. Example: ‘abcabcbb’ → 3 (‘abc’).
Approach: Sliding window with a map (or last-seen index) of characters. Expand the right pointer; when a duplicate appears inside the window, move the left pointer past the previous occurrence.
Complexity: O(n) time
IOCL tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Coding Q8: Merge overlapping intervals
Problem: Given a list of intervals [start, end], merge all overlapping intervals and return the non-overlapping set that covers the same ranges.
Approach: Sort by start time. Walk once, merging into the last interval in the result when the next start is ≤ current end; otherwise append a new interval.
Complexity: O(n log n) time from the sort
IOCL tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Deep prep notes for IOCL
How the IOCL gate-based recruitment usually feels
Students usually say the first round is time-tight - easy marks vanish if you sit too long on one hard question. For IOCL, skim the paper in a couple of minutes, mark what you can finish cleanly, and protect accuracy. Languages people commonly use: N/A for core.
Topic weight hints
| Area | Why it matters at IOCL |
|---|---|
| GATE technical | What usually helps you clear the first round |
| Core CS (OOPs / DBMS / OS) | Technical interview depth |
| Oil Refining & Marketing PSU awareness | Helps in managerial / HR conversations |
| Communication | Explain your approach clearly; keep a few real examples ready for HR |
14-Day sprint
- Days 1-3: Learn the 2025 pattern and take two sectional mocks
- Days 4-7: Closed practice on weak topics from your error log
- Days 8-10: Full mocks every other day; review the same day
- Days 11-14: Practice explaining projects out loud, light revision, sleep and IDs ready