Q64.Let Tn be the number of all possible triangles formed by joining vertices of an n-sided regular polygon. If Tn+1 โTn = 10 , then the value of n is : (1) 10 (2) 8 (3) 5 (4) 7
What This Question Tests
This question requires forming an equation based on the formula for combinations (number of ways to choose 3 vertices from n to form a triangle) and then solving it for n.
Concepts Tested
Formulas Used
nCr = n! / (r! * (n-r)!)
nC3
๐ NCERT Sections This Tests
2.2 โ A Regular Hexagon Of Side 10 Cm Has A Charge 5 Mc At Each Of Its
Physics Class 11 ยท Chapter 2
2.2 A regular hexagon of side 10 cm has a charge 5 mC at each of its vertices. Calculate the potential at the centre of the hexagon.
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?
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5.11 Draw all the isomers (geometrical and optical) of: (i) [CoCl2(en)2] + (ii) [Co(NH3)Cl(en)2] 2+ (iii) [Co(NH3)2Cl2(en)]+
๐ Question Details
- Chapter
- Permutation & Combination
- Topic
- Combinations for forming triangles
- Year
- 2013
- Shift
- 07 Apr
- Q Number
- Q64
- Type
- MCQ
- NCERT Ref
- Class 11 Mathematics Ch 7: Permutations and Combinations
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