Find the greatest common factor (GFC) of 24, 40 and 60.	Choose the correct answer
A) 1
B) 2
C) 3
D) 4
E) 5

Rationale: we first write the prime factorization of each given number 24 = 2 × 2 × 2 × 3 = 23 * cubic * × 3 40 = 2 × 2 × 2 × 5 = 23 * cubic * × 5 60 = 2 × 2 × 3 × 5 = 22 * square * × 3 × 5 gfc = 22 * square * = 4 corect answer is d ) 4
Answer: D