Question

The number of one-one functions that can be defined from A =(4,8,12,16) to B is 5040, the n(B)

Answer 1

GIVEN n(A)=4 and no:of one-one function is 5040

so we should find n(B)=

First do n!/(n-m)!=5040

next substitute n!/(n-4)!=5040

= n(n-1)(n-2)(n-3)(n-4)!/(n-4)!=5040

=n(n-1)(n-2)(n-3)=5040

next substitute the big digit in the given options and substitute then you will get LHS=RHS

Other wise it is descriptive take the digits after 5 as the question indicating the bigger value 5040

so then 10(10-1)(10-2)(10-3)=5040

10*9*8*7=5040

So LHS=RHS