Quantitative Aptitude • Number System & SimplificationHard
How many factors (divisors) does 150 have, including 1 and the number itself?
A. 4
B. 12✓ Correct Answer
C. 7
D. 10
💡 Solution & Explanation
Write the number as a product of primes: 150 = 2 × 3 × 5^2. A factor can use each prime from power 0 up to its full power, so the number of factors = (1 + 1) × (1 + 1) × (2 + 1) = 12. Multiplying (exponent + 1) for each prime is much faster than listing every factor.
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