Q23.The number of ways, 5 boys and 4 girls can sit in a row so that either all the boys sit together or no two boys sit together, is -
What This Question Tests
This question requires calculating permutations for two mutually exclusive conditions: all boys sit together (block method) and no two boys sit together (gap method), and then summing the results.
Concepts Tested
Formulas Used
n! (permutations of n distinct items)
P(n,k) = n! / (n-k)!
๐ NCERT Sections This Tests
5.12 โ Write All The Geometrical Isomers Of [Pt(Nh3)(Br)(Cl)(Py)] And How Many Of
Chemistry Class 11 ยท Chapter 5
5.12 Write all the geometrical isomers of [Pt(NH3)(Br)(Cl)(py)] and how many of these will exhibit optical isomers?
2.1 โ Arrange The Following Metals In The Order In Which They Displace Each Other
Chemistry Class 11 ยท Chapter 2
2.1 Arrange the following metals in the order in which they displace each other from the solution of their salts. Al, Cu, Fe, Mg and Zn.
1.3 โ Define The Following Terms:
Chemistry Class 11 ยท Chapter 1
1.3 Define the following terms: (i) Mole fraction (ii) Molality (iii) Molarity (iv) Mass percentage.
๐ Question Details
- Chapter
- Permutation & Combination
- Topic
- Arrangement with conditions
- Year
- 2025
- Shift
- 23 Jan Shift 2
- Q Number
- Q23
- Type
- Numerical
- NCERT Ref
- Class 11 Mathematics Ch 7: Permutations and Combinations
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