Unit Digit Questions with Solutions | Set 1 (Q1 to Q10)

This set contains Unit Digit Questions with Solutions — Set 1 (Q1 to Q10) covering a mix of question types and difficulty levels — from basic to advanced — exactly as asked in real competitive exams.

Solutions are written in a simple, step-by-step notebook style for easy self-study and quick understanding. Each solution is broken down step by step so even the toughest question feels easy. These questions are hand-picked for students preparing for SSC CGL, SSC CHSL, CAT, Bank PO, Bank Clerk, UPSC CSAT, Railway RRB, AMCAT, eLitmus, TCS NQT and all campus placement aptitude tests. International students preparing for GRE, GMAT, SAT, ACT, MAT and all Numerical Reasoning Tests will find these equally useful.

✏️ Attempt each question on your own first — then check the solution below.

1. Find the unit digit of product of all odd prime numbers.

2. Find the unit digit of 583 × 782 ×216 × 424

3. Find the unit digit of product of all even numbers.

4. Find the unit digit of 5!

5. Find the unit digit of 4!

6. Find the unit digit of (3952)³⁷¹⁹

7. Find the unit digit of (80076526)⁴⁶⁶⁵²

8. Find the unit digit of (490087054)³⁹²⁰⁵⁸⁴

9. Find unit digit of (2.34589)¹⁰⁵⁹

10. Find the unit digit of (8908050225)⁵⁸⁹⁴

1. Find the unit digit of product of all odd prime numbers.
Sol:
We know that if we multiply by 5 to any odd prime number the result will always give unit digit 5.
Hence required unit digit will be 5.    Answer

2. Find the unit digit of 583 × 782 ×216 × 424
Sol:

3. Find the unit digit of product of all even numbers.
Sol:
Some of the starting even numbers are:
2, 4, 6, 8, ⑩, 12, 14, …………
Zero multiplied by any number gives result zero.
Hence required number = 0      Answer

4. Find the unit digit of 5!
Sol:

Hence we can say any factorial number greater than or equal to 5! has unit digit as Zero.

5. Find the unit digit of 4!
Sol:
4! = 4 × 3 × 2 × 1 = 24 ⟶ 4   Answer

6. Find the unit digit of (3952)³⁷¹⁹
Sol:
\(\frac{{3719}}{4}\) ⟶ R = 3
∴ Uₔ = (2)³ = 8      Answer

7. Find the unit digit of (80076526)⁴⁶⁶⁵²
Sol:
Since Uₔ of base is 6
∴ Uₔ of number = 6        Answer

8. Find the unit digit of (490087054)³⁹²⁰⁵⁸⁴
Sol:
\(\frac{{39020584}}{4}\) ⟶ R = 0
& base has Uₔ 4 i.e. even
∴ Uₔ of given numbers = 6

9. Find unit digit of (2.34589)¹⁰⁵⁹
Sol:
\(\frac{{1059}}{4}\) ⟶ R = 3
base Uₔ = 9
∴ Uₔ of number = (9)³ = 9      Answer

10. Find the unit digit of (8908050225)⁵⁸⁹⁴
Sol:
Since base has Uₔ = 5
Hence Uₔ of number = 25     Answer

✅ Well done on completing Set 1!

Continue practising with Unit Digit Questions 11 to 20 → Set 2 or revisit the Unit Digit Concept Page to strengthen your formulas and tricks before moving ahead.

Consistent practice is the key to mastering unit digit for SSC CGL, SSC CHSL, CAT, Bank PO, Bank Clerk, UPSC CSAT, Railway RRB, AMCAT, eLitmus, TCS NQT and international exams including GRE, GMAT, SAT, ACT, MAT and all Numerical Reasoning Tests. Want to understand the concept better? Read about Units Digit on Wikipedia before attempting the next set.

This page is part of our complete series of unit digit questions with solutions for competitive exams — covering every question type from basic to advanced so you can build speed, accuracy and confidence. Practising these questions regularly will also strengthen your core unit digit concept before your exam day.