Question

if nc4=495 then n is​

Answer 1

Answer:

12

Step-by-step explanation:

nc4=495

n!/(n-4)!4!=495

[(n-4)!x(n-3)(n-2)(n-1)(n)]/(n-4)!4!=495                ncr=n!/(n-r)!r!

(n-3)(n-2)(n-1)(n)=495x4!                                    n!=(n-1)!n

=495x1x2x3x4

=495x24

prime factorising

495/5/9=11

=5x9x11x2x3x4

(n-3)(n-2)(n-1)n=9x10x11x12

n-2=10

n=10+2

n=12