RankLab
Back to Questions
MathsMediumMCQ2019 · 10 Jan Shift 2

Q63.If ∑25r=0{(50Cr)(50−rC25−r)} = K(50C25) , then K is equal to (1) 225 (2) 225 −1 (3) 224 (4) (25)2 is 720, is

What This Question Tests

This question tests the ability to recognize and apply a specific identity for products of binomial coefficients and then use the formula for the sum of binomial coefficients.

Concepts Tested

Binomial coefficients identitiesSum of binomial coefficients

Formulas Used

C(n,r) * C(n-r, k-r) = C(n,k) * C(k,r)

Sum (nCr from r=0 to n) = 2^n

📚 NCERT Sections This Tests

5.28How Many Ions Are Produced From The Complex Co(Nh3)6Cl2 In Solution?

Chemistry Class 11 · Chapter 5

70% match

5.28 How many ions are produced from the complex Co(NH3)6Cl2 in solution? (i) 6 (ii) 4 (iii) 3 (iv) 2 139 Coordination Compounds Reprint 2025-26

2.2A Regular Hexagon Of Side 10 Cm Has A Charge 5 Mc At Each Of Its

Physics Class 11 · Chapter 2

69% match

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.

12.5A Hydrogen Atom Initially In The Ground Level Absorbs A Photon,

Physics Class 12 · Chapter 12

69% match

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.