L&T Technology Services Placement Papers 2026 - Questions and Solutions

Last Updated: March 2026

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Company Overview

L&T Technology Services (LTTS) is a leading global ER&D services company, part of the Larsen & Toubro Group. The company provides engineering, research, and development services across various industries including transportation, industrial products, telecom, and healthcare.

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Selection Process

Stage	Description	Duration
Online Assessment	Aptitude, Technical MCQ, Coding	90 minutes
Technical Interview	CS fundamentals, Projects	45-60 minutes
HR Interview	Behavioral, Culture fit	30 minutes

Eligibility:

• 60% in 10th, 12th, Graduation
• No active backlogs
• All branches eligible

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Exam Pattern

Section	Questions	Time	Topics
Quantitative	20	25 min	Aptitude, Reasoning
Technical	20	25 min	CS fundamentals
Coding	2	40 min	Algorithms

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Aptitude Questions

1. A train 180m long running at 72 km/hr crosses a platform in 20 sec. Find platform length.

Solution: Speed = 72 × 5/18 = 20 m/s Distance = 20 × 20 = 400m Platform = 400 - 180 = 220 meters

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2. Find next: 2, 6, 12, 20, 30, 42, ?

Solution: Pattern: n(n+1) 1×2=2, 2×3=6, 3×4=12... 6×7=42 Next = 7×8 = 56

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3. A can do work in 15 days, B in 10 days. Together with C, they finish in 5 days. Find C's time alone.

Solution: 1/15 + 1/10 + 1/C = 1/5 1/C = 1/5 - 1/15 - 1/10 = (6-2-3)/30 = 1/30 C = 30 days

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4. CP of 50 articles equals SP of 40 articles. Find profit%.

Solution: 50×CP = 40×SP → SP/CP = 50/40 = 5/4 Profit = 1/4 = 25%

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5. A sum doubles in 5 years at SI. Find time to become 4 times.

Solution: Rate = 100/5 = 20% To become 4 times: 3 times interest needed Time = 3×5 = 15 years

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6. Average of 11 numbers is 50. Average of first 6 is 45, last 6 is 55. Find 6th number.

Solution: Sum of 11 = 550 Sum of first 6 = 270 Sum of last 6 = 330 6th number = 270 + 330 - 550 = 50

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7. Present ages ratio 5:7. 10 years ago, ratio was 3:4. Find present ages.

Solution: Let ages be 5x and 7x (5x-10)/(7x-10) = 3/4 20x - 40 = 21x - 30 x = 10 Ages: 50 and 70 years

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8. A man rows at 5 km/hr in still water. Against stream at 3 km/hr. Find stream speed.

Solution: Upstream speed = Boat speed - Stream speed 3 = 5 - Stream Stream = 2 km/hr

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9. How many 4-digit numbers divisible by 5 can be formed using 0,1,2,3,4 without repetition?

Solution: Last digit must be 0: First: 4 choices (1-4), Second: 3, Third: 2, Fourth: 1 (0) = 4×3×2×1 = 24

Last digit must be 5: Not possible (5 not in set)

Total = 24

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10. Probability of drawing two kings from a deck.

Solution: P = (4/52) × (3/51) = 12/2652 = 1/221

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Technical Questions

1. Difference between C and C++

• C: Procedural, no OOP, manual memory management
• C++: Object-oriented, supports classes, templates, STL

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2. What is polymorphism?

• Compile-time: Method overloading
• Runtime: Method overriding

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3. Explain virtual functions

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4. What is a constructor?

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5. Difference between stack and queue

• Stack: LIFO (Last In First Out)
• Queue: FIFO (First In First Out)

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6. What is normalization?

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7. Explain primary key and foreign key

• Primary key: Uniquely identifies each row
• Foreign key: Links to primary key of another table

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8. What is the difference between compiler and interpreter?

• Compiler: Translates entire program at once
• Interpreter: Translates line by line during execution

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9. What is recursion?

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10. Explain time complexity of binary search

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Coding Questions

1. Check if a number is prime.

def is_prime(n):
    if n <= 1:
        return False
    if n <= 3:
        return True
    if n % 2 == 0 or n % 3 == 0:
        return False
    
    i = 5
    while i * i <= n:
        if n % i == 0 or n % (i + 2) == 0:
            return False
        i += 6
    
    return True

# Test
print(is_prime(17))  # True
print(is_prime(18))  # False

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2. Calculate factorial.

def factorial(n):
    if n == 0 or n == 1:
        return 1
    result = 1
    for i in range(2, n + 1):
        result *= i
    return result

# Or recursive
def factorial_recursive(n):
    if n <= 1:
        return 1
    return n * factorial_recursive(n - 1)

# Test
print(factorial(5))  # 120

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3. Find length of string without using len().

def string_length(s):
    count = 0
    for _ in s:
        count += 1
    return count

# Test
print(string_length("hello"))  # 5

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4. Sum of digits of a number.

def sum_of_digits(n):
    total = 0
    while n > 0:
        total += n % 10
        n //= 10
    return total

# Or recursive
def sum_digits_recursive(n):
    if n == 0:
        return 0
    return n % 10 + sum_digits_recursive(n // 10)

# Test
print(sum_of_digits(12345))  # 15

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5. Print Fibonacci series up to n terms.

def fibonacci(n):
    if n <= 0:
        return []
    if n == 1:
        return [0]
    
    fib = [0, 1]
    for i in range(2, n):
        fib.append(fib[i-1] + fib[i-2])
    
    return fib

# Test
print(fibonacci(10))  # [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]

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Interview Tips

1. Focus on engineering fundamentals
2. Practice coding in C/C++/Java
3. Understand your projects deeply
4. Research LTTS business domains
5. Prepare for technical aptitude
6. Practice problem-solving
7. Show interest in engineering services

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Best of luck with your L&T Technology Services placement!