Question 29

If the coefficient of $$x^{12}$$ in the expansion of $$(x^3 + 1)^m$$ is 210, then the coefficient of $$x^{15}$$ is

Solution

If m = 10 => $$10_{C_6}\left(x^3\right)^4\left(1\right)^6=\ 210x^{12}$$

Hence $$10_{C_5}\left(x^3\right)^5\left(1\right)^5=\ 252x^{15}$$


Create a FREE account and get:

  • All Quant Formulas and shortcuts PDF
  • 40+ previous papers with solutions PDF
  • Top 500 MBA exam Solved Questions for Free

cracku

Boost your Prep!

Download App