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

Last Updated: March 2026

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.

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

Exam Pattern

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

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

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

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

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%

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

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

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

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

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

10. Probability of drawing two kings from a deck.

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

Technical Questions

1. Difference between C and C++

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

2. What is polymorphism?

Compile-time: Method overloading
Runtime: Method overriding

3. Explain virtual functions

4. What is a constructor?

5. Difference between stack and queue

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

6. What is normalization?

7. Explain primary key and foreign key

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

8. What is the difference between compiler and interpreter?

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

9. What is recursion?

10. Explain time complexity of binary search

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

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

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

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

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]

Interview Tips

Focus on engineering fundamentals
Practice coding in C/C++/Java
Understand your projects deeply
Research LTTS business domains
Prepare for technical aptitude
Practice problem-solving
Show interest in engineering services

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