JEE Main2005MathematicsBinomial TheoremActual
The value of ⁵⁰ C ₄+ _ r =1 ^6 ^ 56-r C ₃ is
Options
- A⁵⁵ C ₄
- B⁵⁵ C ₃
- C⁵⁶ C ₃
- D⁵⁶ C ₄
Correct answer
D. ⁵⁶ C ₄
Step-by-step solution
aligned & ⁵⁰ C ₄+ _ r =1 ^6 ^ 56-r C ₃ & ⁵⁰ C ₄+ [ ⁵⁵ C ₃+ ⁵⁴ C ₃+ ⁵³ C ₃+ ⁵² C ₃+ ⁵¹ C ₃+ ⁵⁰ C ₃ ] & = ( ⁵⁰ C ₄+ ⁵⁰ C ₃ )+ ⁵¹ C ₃+ ⁵² C ₃+ ⁵³ C ₃+ ⁵⁴ C ₃+ ⁵⁵ C ₃ & ( ⁵¹ C + ⁵¹ C )+ ⁵² C ₃+ ⁵³ C ₃+ ⁵⁴ C ₃+ ⁵⁵ C ₃ & ⁵⁵ C ₄+ ⁵⁵ C ₃= ⁵⁶ C ₄ . aligned