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 |
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
C.
81
If the last two digits is 0, 0, then in Ist digit any of the numbers except 0
i.e., 9 numbers
If the last two digits is 1, 1, then in Ist digit any of the numbers except 0 and 1, i.e. 8 numbers