How many positive divisors does 45 have?
Answer and explanation
Correct answer: A. 6
- Step 1: Prime factorisation: .
- Step 2: The number of divisors is .
Answer
6.
Why not the others: 3: it counts prime factors with repetition, not divisors. 4: it uses the number of distinct primes only.
Practise more Properties of Integers.
Free questions with an explanation for every one, and full timed EJU Japan mock tests.