Observe the following lists
List I | List II |
(A) [a b c] | 1. |
(B) | 2 .(a . c)b - (a . b) c |
(C) | 3. |
(D) a . b | 4. |
5. (b . c)a - (a . b)c |
Then the correct match for List I from List II is
A. A B C D | (i) 1 2 3 4 |
B. A B C D | (ii) 3 5 2 1 |
C. A B C D | (iii) 3 5 5 1 |
D. A B C D | (iv) 3 2 5 1 |
A. A B C D | (i) |
B. A B C D | (ii) |
C. A B C D | (iii) |
D. A B C D | (iv) |
If N denotes the set of all positive integers and if f : efined by f(n) = the sum of positive divisors of n then, f(2k, 3), where k is a positive integers, is
2k + 1 - 1
2(2k + 1 - 1)
3(2k + 1 - 1)
4(2k + 1 - 1)
A three digit numbern is such that the last twodigits of it are equal and differ from the first. The number of such n's is
64
72
81
900