Question

Let X = the number of nonzero digits in a randomly selected 4-digit PIN that has no restriction on the digits. What are the possible values of X?(multiple choice)(a) 0, 1, 2, 3, 4, ...(b) 1, 2, 3, 4, ...(c) 1, 2, 3, 40, 1, 2, 3(d) 0, 1, 2, 3, 4For the following possible outcomes, give their associated X values.PIN | associated value1020 | ?2478 | ?7130 | ?

Answer 1

Explanation:

in a 4-digit number : how many 0 can there be ?

can there be five 0s ?

no, how could there be ? there is no space for five 0s, when there are only 4 positions for digits.

it is said that there are no restrictions on the digits.

so, any digit can occur at any position.

that means simply that there can be

no 0s : e.g. 1234

one 0 : e.g. 1204

two 0s : e.g. 1030

three 0s : e.g. 0030 or 7000 ...

four 0s - only one possibility : 0000

so, the possible values for X are

0, 1, 2, 3, 4

please pick the corresponding answer in your list, as you clearly made some typos there. I cannot tell the difference between some of the options you provided.

the X value for 1020 is 2

the X value for 2478 is 0

the X value for 7130 is 1

if there are more numbers, you did not list them.