BITSAT2023MathematicsBinomial TheoremActual
The middle term in the expansion of ( 10 x + x 10 )¹⁰ is
Options
- A¹⁰ C ₅
- B¹⁰ C ₆
- C¹⁰ C ₅ 1 x¹⁰
- D¹⁰ C ₅ x ¹⁰
Correct answer
A. ¹⁰ C ₅
Step-by-step solution
General term =T_ r+1 = ¹⁰ C _r ( 10 x )^ 10-r ( x 10 )^r Here n=10 , which is an even number. Now, [ 10 2 +1 ]^ th term i.e. 6^ th term is the middle term. Hence, middle term =T₆ T _ 5+1 = ¹⁰ C ₅ ( 10 x )¹⁰⁻⁵ ( x 10 )^5 = ¹⁰ C ₅ ( 10 x )^5 ( x 10 )^5= ¹⁰ C ₅ .