to find 'n; :-
(n-6)! / (n-4)! =6

Asked by Gishin Rajan | 3rd Sep, 2014, 11:05: PM

Expert Answer:

fraction numerator open parentheses n minus 6 close parentheses factorial over denominator open parentheses n minus 4 close parentheses factorial end fraction equals open parentheses n minus 6 close parentheses open parentheses n minus 5 close parentheses equals 6  n squared minus 11 n plus 30 equals 6 n squared minus 8 n space minus 3 n space plus 24 equals 0 open parentheses n minus 8 close parentheses open parentheses n minus 3 close parentheses equals 0  rightwards double arrow space n equals 3 space o r space 8 space b u t space n greater or equal than 6 space open parentheses because n minus 6 greater or equal than 0 close parentheses  s o space n equals 8 space i s space t h e space r e q u i r e d space v a l u e

Answered by Dharma Teja | 3rd Sep, 2014, 11:24: PM