${(n - 1)}_{p_{3}} : n_{p_{4}} = 1 : 4$ find $n$

Open in App

Solution

$^{n} p_{x} = \frac{n!}{(n - x)!}$

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

$\frac{1}{n} = \frac{1}{4}$

$n = 4$

Suggest Corrections

Similar questions

Find n if $^{n - 1} P_{3} :^{n} P_{4} = 1 : 9.$

n

^{n - 1} P_{3} :^{n} P_{4} = 1 : 9.

(i) If $^{n} P_{4} :^{n} P_{5} = 1 : 2$ find n.

(ii) If $^{n - 1} P_{3} :^{n + 1} = 5 : 12,$ find n.

^{n} p_{4} :^{n - 1} p_{3} = 9 : 1

5 \times^{n} P_{3} = 4 \times^{n + 1} P_{3},

n = ?

Join BYJU'S Learning Program