The total number of ways of selecting two numbers from the set `{1,2, 3, 4, ........3n}` so that their sum is divisible by 3 is equal to a. `(2n^2-n)/2` b. `(3n^2-n)/2` c. `2n^2-n` d. `3n^2-n`

the total number of ways of selecting two number from the set {1,2,3,4,…..3n} so that their sum divisible by 3 is equal to -

If the number of ways of selecting 3 numbers out of 1, 2, 3, ……., 2n+1 such that they are in arithmetic progression is 441, then the sum of the divisors of n is equal to

If the number of ways of selecting 3 numbers out of 1, 2, 3, ……., 2n+1 such that they are in arithmetic progression is 441, then the sum of the divisors of n is equal to

Out of 3n consecutive integers, three are selected at random. Show that the chance that their sum is divisible by 3 is (3n^(2)-3n+2)/((3n-1)(3n-2))

The probability that a randomly selected 2-digit number belongs to the set { n in N: (2^(n)-2) is a multiple of 3} is equal to

n is selected from the set {1, 2, 3,.............,100} and the number 2^n+3^n+5^n is formed. Total number of ways of selecting n so that the formed number is divisible by 4 is equal to (A) 50 (B) 49 (C) 48 (D) None of these.

n is selected from the set {1, 2, 3,.............,100} and the number 2^n+3^n+5^n is formed. Total number of ways of selecting n so that the formed number is divisible by 4 is equal to (A) 50 (B) 49 (C) 48 (D) None of these.

n is selected from the set {1, 2, 3,.............,100} and the number 2^n+3^n+5^n is formed. Total number of ways of selecting n so that the formed number is divisible by 4 is equal to (A) 50 (B) 49 (C) 48 (D) None of these.

If 1+(1+2)/2+(1+2+3)/3+ddotto\ n terms is Sdot Then, S is equal to a. (n(n+3))/4 b. (n(n+2))/4 c. (n(n+1)(n+2))/6 d. n^2

If 1+(1+2)/2+(1+2+3)/3+ddotto\ n terms is Sdot Then, S is equal to a. (n(n+3))/4 b. (n(n+2))/4 c. (n(n+1)(n+2))/6 d. n^2