Question

The greatest term in expansion of (2x + 5y)¹³ when x = 10 and y = 2 is –

• A. ¹³C₆ (20)⁷ (10)⁴
• B. ¹³C₅ (20)⁸ (10)⁵
• C. ¹³C₄ (20)⁹ (10)⁴
• D. None of these

Answer 1

Answer: (B)

¹³C₅ (20)⁸ (10)⁵

Answer 2

Calculate $\frac{(n + 1).|II^{nd}member|}{|I^{st}member| + |II^{nd}member|}$

= $\frac{(13 + 1).|5.2|}{|(2).(10)| + |5.2|}$ = $\frac{14 \times 10}{20 + 10}$ = $\frac{14}{3}$ = 4.6 Ļ Z

T_[4.6]+1 = Num. greatest = T₆

T₆ = ¹³C₅. (20)⁸.(10)⁵