The value of n in $^{n} C_{4} = 5^{n - 1} C_{r}$ is

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D 5
$^{n} C_{4} = 5^{n - 1} c_{4}$
( $r$ should be $4$ )

$\frac{n!}{(n - 4)! 4!} = \frac{5 (n - 1)!}{(n - 5)! 4!}$

$\frac{n (n - 1)!}{(n - 4) (n - 5)!} = \frac{5 (n - 1)!}{(n - 5)!}$

$n = 5 n - 20$

$20 = 4 m$

$n = 5$

Suggest Corrections

Similar questions

^{n - 1} C_{r - 2} +^{n - 1} C_{r - 1}

^{n} C_{r} +^{n} C_{r - 1}

^{n + 1} C_{r + 1} :^{n} C_{r} :^{n - 1} C_{r - 1} = 11 : 6 : 3

n

r

^{n} C_{4},^{n} C_{5} a n d^{n} C_{6}

(\begin{matrix} 513 \end{matrix}) + (\begin{matrix} 503 \end{matrix}) + (\begin{matrix} 493 \end{matrix}) + (\begin{matrix} 483 \end{matrix}) + (\begin{matrix} 473 \end{matrix}) + (\begin{matrix} 474 \end{matrix})

(\begin{matrix} 524 \end{matrix})

^{n - 1} C_{r} +^{n} C_{r + 1} =^{n + 1} C_{r + 1}

Join BYJU'S Learning Program