If numbers 1,2,3,4,5 are to be used in a five number code, how many different codes are possible if repetitions are not permitted

step-by-step explanation:

the multiplicative inverse of a fraction a/b is b/a. for the multiplicative inverse of a real number, divide 1 by the number. for example, the reciprocal of 5 is one fifth 1/5 or 0.2, and the reciprocal of 0.25 is 1 divided by 0.25, or 4.

the answer is b.)

< 1=< 2