Permutation & Combination Test
Number of questions:10
Q.1 X is one of the numbers selected from the first 100 natural numbers, what is the probability that (X + 50/X) is greater than 50?
Q.2 The letters ‘ABELST’ are arranged (with no repetition) in dictionary order, which contains only 6 letter words. What is the rank of the word ‘STABLE’ in this order?
Q.3 The lengths of the sides of a non-isosceles triangle are 5, x and 15 (5 x < 15). How many integral values of x are possible?
Q.4 A cube of side 12 cm is painted red on all the faces and then cut into smaller cubes, each of side 3 cm. What is the total number of smaller cubes having none of their faces painted?
Q.5 A man has nine friends, four boys and five girls. In how many ways can he invite them, if there have to be exactly three girls in the invitees?
Q.6 Raju has 128 boxes with him. He has to put atleast 120 oranges in one box and 144 at the most. Find the least number of boxes which will have the same number of oranges.
Q.7 Let n be the number of different 5-digit numbers, divisible by 4 with the digits 1, 2, 3, 4, 5 and 6, with no digit being repeated. What is the value of n?
Q.8 How many 3 digit number can be formed with the digits 5, 6, 2, 3, 7 and 9 which are divisible by 5 and none of its digit is repeated?
Q.9 How many words can be formed from the letters of the word ‘DIRECTORY’ So that the vowels are always together?
Q.10 If a fair coin is tossed twice, what is the probability that on the first toss the coin lands heads and on the second toss the coin lands tails?
