Let `S={1,2,...,20}.` A subset `B` of `S` is said to be `''nice''`, if the sum of the elements of `B` is 203. Then the probability that a randomly chosen subset of `S` is `''nice''` is: (a) `7/(2^20)` (b) `5/(2^20)` (c) `4/(2^20)` (d) `6/(2^20)`

Let S={1,2,3, …, 100} . The number of non-empty subsets A to S such that the product of elements in A is even is

Let set A = { 1, 2, 3, ….., 22} . Set B is a subset of A and B has exactly 11 elements, find the sum of elements of all possible subsets B .

If S = {1, 2, 3,…,20}, K = {a, b, c, d}, G = {b, d, e, f}. The number of elements of (SxxK) uu (SxxG) is

Let S = {1,2,3,..., 40} and let A be a subset of S such that notwo elements in A have their sum divisible by 5. What is themaximum number of elements possible in A?

Let S = {1,2,3,.............. n} and A={(a ,b)"|"1lt=a ,blt=n}=SxxS . A subset B of A is such that (x ,x) in B for every x in Sdot Then find the number of subsets Bdot

S is a set containing n elements. A subset AS of S is selected . The set S is reconstructed by replacing the elements of A.A subset B of S is now selected. If the numer of ways of selecting subsets A and B of S such that AcapB=phi is 81, then n= (A) 3 (B) 4 (C) 5 (D) none of these

A speaks truth in 75% cases and B speaks truth in 80% cases. Probability that they contradict each other in statement, is 7/(20) b. (13)/(20) c. 3/5 d. 2/5

A bag contains 20 coins. If the probability that the bag contains exactly 4 biased coin is 3/4 and that of exactly 5 biased coin is 2/3, then the probability that all the biased coin are sorted out from bag is exactly 10 draws is 5/(10)(^(16)C_6)/(^(20)C_9)+1/(11)(^(15)C_5)/(^(20)C_9) b. 2/(33)[(^(16)C_6+5^(15)C_5)/(^(20)C_9)] c. 5/(33)(^(16)C_7)/(^(20)C_9)+1/(11)(^(15)C_6)/(^(20)C_9) d. none of these

If a : b=2:5, then (3a+2b)/(4a+b)= (a) (16)/(13) (b) (13)/(16) (c) (25)/(22) (d) (20)/(21)

If tan A/2=5/6,Tan B/2=20/37. Then sides are in