2012 · Q40
Consider the following statements:
- 1If n is a prime number greater than 5, then n^4 - 1 is divisible by 2400.
- 2Every square number is of the form 5n or (5n - 1) or (5n + 1) where n is a whole number.
Which of the above statements is/are correct?
Elementary MathematicsNumber System
- A1 only
- B2 only
- CBoth 1 and 2
- DNeither 1 nor 2
Explanation
Statement 1 fails for n = 11 (14640 is not divisible by 2400); statement 2 holds since squares mod 5 are 0, 1 or 4.