What number less than 100 has exactly 4 prime factors?
There is more than one possible answer.
The prime factors of 16 are 2, 2, 2, and 2. It has four prime
factors, but only one distinct prime factor.
The prime factors of 24 are 2, 2, 2, and 3. It has four prime
factors, but only two distinct prime factors.
The prime factors of 36 are 2, 2, 3, and 3. It has four prime
factors, but only two distinct prime factors.
The prime factors of 40 are 2, 2, 2, and 5. It has four prime
factors, but only two distinct prime factors.
The prime factors of 54 are 2, 3, 3, and 3. It has four prime
factors, but only two distinct prime factors.
The prime factors of 56 are 2, 2, 2, and 7. It has four prime
factors, but only two distinct prime factors.
The prime factors of 60 are 2, 2, 3, and 5. It has four prime
factors, but only three distinct prime factors.
The prime factors of 81 are 3, 3, 3, and 3. It has four prime
factors, but only one distinct prime factor.
The prime factors of 84 are 2, 2, 3, and 7. It has four prime
factors, but only three distinct prime factors.
The prime factors of 88 are 2, 2, 2, and 11. It has four prime
factors, but only two distinct prime factors.
The prime factors of 90 are 2, 3, 3, and 5. It has four prime
factors, but only three distinct prime factors.