Compute the permutations and combinations. how many two-digit, positive integers can be formed from the digits 1, 3, 5, and 9, if no digit is repeated?
a. 12
b. 16
c. 24

 The correct option is (a) 12.

Step-by-step explanation:  We are given to find the number of two-digit positive integers that can be formed from the digits 1, 3, 5, and 9, if no digit is repeated.

Here, we have 4 digits, out of which we have to choose the digits for the two places.

For first place, we have 4 options.

Since no digit is repeated, so we have 3 options for the second place.

Therefore,

the number of two-digit positive integers that can be formed from the digits 1, 3, 5, and 9, if no digit is repeated is given by the permutation of 4 digits taken 2 at a time.

Thus, the total number of two-digit positive integers will be

Option (a) is CORRECT.

the graph in the attached figure

step-by-step explanation:

we have

using a graphing tool

the graph in the attached figure

the roots are ( x-intercepts) x=-0.5,x=1,x=3

the y-intercept is the point (0,3)