The total number of ways of selecting six coins out of 20 one-rupee coins, 10 fifty-paisa coins, and 7 twenty-five paisa coins is: (a.) `28` (b.) `56` (c.) `^37 C_6` (d.) none of these

The total number of ways in which a beggar can be given at least one rupee from four 25- paise coins, three 50-paisa coins and 2 one-rupee coins, is

If n objects are arrange in a row, then the number of ways of selecting three of these objects so that no two of them are next to each other is a. "^(n-2)C_3 b. "^(n-3)C_2 c. "^(n-3)C_3 d. none of these

20 persons are sitting in a particular arrangement around a circular table. Three persons are to be selected for leaders. The number of ways of selection of three persons such that no two were sitting adjacent to each other is a. 600 b. 900 c. 800 d. none of these

In a polygon, no three diagonals are concurrent. If the total number of points of intersection of diagonals interior to the polygon is 70, then the number of diagonals of the polygon is a. 20 b. 28 c. 8 d. none of these

The number of ways in which we can select four numbers from 1 to 30 so as to exclude every selection of four consecutive numbers is a. 27378 b. 27405 c. 27399 d. none of these

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

A bag contains 10 rupee - coins, 7 fifty-paise coins and 4 twenty finve-paise coins. Fine the probability of drawing (i) a rupee-coin (ii) three rupee-coins and (iii) three coins, one of each type, in the random drawing of three coins from the bag.

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.

The number of possible outcomes in a throw of n ordinary dice in which at least one of the die shows and odd number is a. 6^n-1 b. 3^n-1 c. 6^n-3^n d. none of these

Among the 8! [permutations of the digits 1, 2, 3..., 8, consider those arrangements which have the following property. If we take any five consecutive positions the product of the digits in these positions is divisible by 5. The number of such arrangements is equal to a. 7! b. 2.(7!) c. 7C_4 d. none of these