ARM OA Experience 2026 | 90 Minutes | Aptitude + Technical + 2 Coding Questions

ARM OA Experience 2026 | 90 Minutes | Aptitude + Technical + 2 Coding Questions

I recently gave the ARM Online Assessment and wanted to share the pattern and all the questions I can remember. Hopefully this helps others preparing for ARM.

The overall structure was quite similar to the Texas Instruments OA pattern.

OA Pattern

Total Duration: 90 minutes

Section 1: Aptitude

• 15 Questions
• 20 Minutes

Section 2: Technical

• 30 Minutes

Section 3: Coding

• 2 Coding Questions
• 40 Minutes

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Coding Questions

Coding Question 1 - Consecutive Sum of K Positive Integers

We were given:

S, E, K

We had to find numbers in the inclusive range:

[S, E]

such that the number could be represented as the sum of K consecutive positive integers and also satisfied the required divisibility condition with K.

We then had to return/count the numbers satisfying the conditions.

The main idea involved understanding when a number can be represented as:

x + (x+1) + (x+2) + ... + (x+K-1)

for some positive integer x.

The sum becomes:

K*x + K*(K-1)/2

So this question was mainly based on:

• Mathematics
• Consecutive integer sums
• Divisibility
• Range checking

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Coding Question 2 - Number to Encoded Character

We were given an integer:

1 <= X <= 1000

and had to return an encoded alphabet character.

Examples I remember:

1 -> C
2 -> F

The alphabet positions were considered as:

A = 1
B = 2
C = 3
...

The encoding logic involved adding something like:

2 * X

to the original value.

So:

X = 1

1 + 2*1 = 3
3 -> C

and:

X = 2

2 + 2*2 = 6
6 -> F

For larger values, the alphabet encoding had to be handled according to the rule given in the question.

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Aptitude Questions I Remember

1. Calendar Question

If the 18th day of a month is Tuesday, what day of the week was the 1st day of that month?

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2. Data Interpretation

There were around 2–3 questions based on a graph.

Questions involved interpreting values, percentages, comparisons, etc.

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3. Odd/Even Numbers

Given:

a × b = odd

Which of the following is true?

Options were similar to:

• a + b is even
• a - b is even
• a and b are both odd
• All of the above

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4. Series / Pattern

Find the next term:

Z2, X4, V8, T16, ___ ?

This involved identifying patterns in both:

• Alphabet positions
• Numbers

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5. Circular Seating Arrangement

There were around 4–5 questions based on a single circular arrangement.

Several people were seated in a circle and we had to determine:

• Who sits opposite whom
• Who sits next to whom
• Position relative to another person
• Possible/definite arrangements

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6. Age Problem

A question was based on the age difference between S and R.

The information was something similar to:

• Difference between the ages of S and R was given.
• When R was born, S was around 28 years old.
• We had to calculate the current age of S using the remaining information given in the question.

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7. Boats and Streams

One question was based on:

• Upstream speed
• Downstream speed

So revise formulas:

Downstream = Boat Speed + Stream Speed
Upstream   = Boat Speed - Stream Speed

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8. Probability – Three Digit Number

A probability question asked about forming a three-digit number satisfying conditions similar to:

• It contains exactly one odd digit
• The number is divisible by 5

We had to find the probability of such a number.

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Technical Questions

9. AVL Tree Rotations

A sequence of numbers was given and we had to construct an AVL Tree.

The question asked:

How many rotations are required while inserting the given numbers?

Important concepts:

• LL Rotation
• RR Rotation
• LR Rotation
• RL Rotation
• Balance Factor

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10. Postfix Expression Evaluation

A postfix expression was given similar to:

23 16 72 51 -3 1 6 1 7 8 + - + *

and we had to calculate the final output.

This required evaluating the postfix expression using a stack.

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11. Pattern Printing – Missing Code Line

A star pattern was given similar to:

  *
 ***
*****
 ***
  *

Some code was already provided and we had to select the missing line of code needed to generate the pattern correctly.

So output tracing and loop conditions were important.

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12. Dynamic Programming Output Question

There was an output-based question on Dynamic Programming.

A code snippet was given and we had to trace the DP array/table and determine the final output.

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13. C/C++ Output Questions

There were around 2–3 more output-based questions.

These required carefully tracing the program rather than writing code.

Good topics to revise:

• Loops
• Arrays
• Increment/decrement operators
• Conditions
• Recursion
• Pointer/array behaviour
• Operator precedence

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14. Circular Queue

There were questions based on Circular Queue.

Important concepts:

front
rear
enqueue
dequeue
overflow
underflow

and conditions such as:

(rear + 1) % size == front

for detecting a full circular queue.

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Topics I Would Recommend Revising for ARM OA

Aptitude

• Calendar
• Probability
• Permutation and Combination
• Boats and Streams
• Ages
• Number Series
• Alphabet Series
• Circular Arrangement
• Data Interpretation
• Odd/Even properties
• Divisibility

Data Structures

• AVL Tree
• BST
• Stack
• Postfix Evaluation
• Circular Queue

Programming

• C/C++ Output Questions
• Loops
• Pattern Printing
• Operator Precedence
• Arrays
• Dynamic Programming

Coding

• Mathematical observations
• Divisibility
• Range-based problems
• Consecutive integer sums
• Character/ASCII encoding
• Modular arithmetic

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Overall Experience

The biggest challenge was time management.

The aptitude section had:

15 questions in 20 minutes

so there was not much time to spend on any single question.

The technical section had several questions where knowing the concept was not enough — you also needed to quickly trace code, evaluate expressions, or construct data structures.

The coding section had 40 minutes for 2 questions, and both questions seemed much easier once the mathematical observation or encoding logic was identified.

For anyone preparing for ARM, I would especially recommend practicing:

Aptitude + C/C++ output questions + AVL Trees + Stack/Postfix + Circular Queue + basic DP + mathematical coding problems.

These are all the questions I can currently remember from the OA.