Q62.The number of four letter words that can be formed using the letters of the word BARRACK is (1) 144 (2) 120 (3) 264 (4) 270 and Bn = 1 βAn . Then, the least odd natural number p
What This Question Tests
This question requires applying principles of permutations and combinations, specifically handling repeated letters, by dividing the problem into cases based on the number of repeated letters in the chosen four-letter word.
Concepts Tested
Formulas Used
nPr = n!/(n-r)!
nCr = n!/(r!(n-r)!)
n!/(p!q!...) for permutations with repetition
π NCERT Sections This Tests
12.5 β A Hydrogen Atom Initially In The Ground Level Absorbs A Photon,
Physics Class 12 Β· Chapter 12
12.5 A hydrogen atom initially in the ground level absorbs a photon, which excites it to the n = 4 level. Determine the wavelength and frequency of photon.
5.12 β Write All The Geometrical Isomers Of [Pt(Nh3)(Br)(Cl)(Py)] And How Many Of
Chemistry Class 11 Β· Chapter 5
5.12 Write all the geometrical isomers of [Pt(NH3)(Br)(Cl)(py)] and how many of these will exhibit optical isomers?
1.3 β Define The Following Terms:
Chemistry Class 11 Β· Chapter 1
1.3 Define the following terms: (i) Mole fraction (ii) Molality (iii) Molarity (iv) Mass percentage.
π Question Details
- Chapter
- Permutation & Combination
- Topic
- Forming words with repeated letters
- Year
- 2018
- Shift
- 15 Apr Shift 2 Online
- Q Number
- Q62
- Type
- MCQ
- NCERT Ref
- Class 11 Mathematics Ch 7: Permutations and Combinations
More from this Chapter
Q85.The set S = {1, 2, 3, β¦ , 12) is to be partitioned into three sets A, B, C of equal size. Thus, A βͺB βͺC = S, A β©B = B β©C = A β©C = Ο . The number of ways to partition S is (1) 12! (2) 12! 3!(4!)3 3!(3!)4 (3) 12! (4) 12! (4!)3 (3!)4
Q74.In a shop there are five types of ice-creams available. A child buys six ice-creams. Statement -1: The number of different ways the child can buy the six ice-creams is 10C5 . Statement β2 : The number of different ways the child can buy the six ice-creams is equal to the number of different ways of arranging 6 A's and 4 B's in a row. (1) Statement β1 is false, Statement β2 is true (2) Statement β1 is true, Statement β2 is true, Statement β2 is a correct explanation for Statement β1 (3) Statement β1 is true, Statement β2 is true; (4) Statement β1 is true, Statement β2 is false. Statement β2 is not a correct explanation for Statement β1.
Q75.How many different words can be formed by jumbling the letters in the word MISSISSIPPI in which no two S are adjacent? (1) 8 β 6C4 β 7C4 (2) 6.8 β 7C4 (3) 6 β 7 β 8C4 (4) 7 β 6C4 β 8C4
Q63.From 6 different novels and 3 different dictionaries, 4 novels and 1 dictionary are to be selected and arranged in a row on the shelf so that the dictionary is always in the middle. Then the number of such arrangements is (1) less than 500 (2) at least 500 but less than 750 (3) at least 750 but less than 1000 (4) at least 1000