1. For each n ∈N,23n−1is divisible by
2. x (xn−1−nan−1)+an(n−1)is divisible by (x−a)2 for
3. 23n−7n−1is divisible by
4. If n is a positive integer, then n3+2nis divisible by
5. If m, n are any two odd positive integer with n < m, then the largest positive integers which divides all the numbers of the type m2− n2 is
6. The smallest positive integer for which the statement 3n+1< 4n holds is
7. P(n) : 2n+2 < 3n, is true for
8. If P(n) : 3n > 4n, then P(n) is true for
9. The inequality n!>2n−1 is true
10. P(n):32n+2−8n−9 is divisible by 64, is true for
11. The statement P(n):1×1!+2×2!+3×3!+....+n×n!=(n+1)!−1 is
12. A student was asked to prove a statement by induction. He proved (i) P(5) is true and (ii) truth of P(n)⇒ truth of P(n+), n ∈N. On the basis of this, he could conclude that P(n) is true
13. The greatest positive integer which divides (n+1)(n+2)(n+3)......(n+r)for n∈Nis
14. Let P(n): n2+nis an odd integer. It is seen that truth of P(n) ⇒the truth of P(n+1). Therefore P(n) is true for all
15. The greatest positive integer, which divides (n+16)(n+17)(n+18)(n+19), for all n ∈N,is
16. If P(x): 2+4+6+....+2n, n∈N,then P(m) =m(m+1)+2 ⇒ P ( m + 1 ) = ( m + 1 ) ( m + 3 ) + 2 ∀ m ∈ N . So we can conclude that P(n) = n(n+1)+2 for
17. The smallest +ve integer n for which n!<(n+12)nholds is
18. If X >−1,then the statement P(n): (1+x)n>1+ nx is true for
19. If P(n): 2n <n!,n∈N,then P(n) is true for
20. If P(n) is a statement such that truth of P(n) ⇒ the truth of P(n+1) for n ∈N,then P(n) is true