There are 3 different roads from city A to city B and 2 different roads from city B to city C. In how many ways can someone go from city A to city C passing by city B and then return back to A? 36, 10, 5, 24

36

Step-by-step explanation:

There are 3 * 2 = 6 ways to go from A to C and then 2 * 3 = 6 ways to go from C to A so the answer is 6 * 6 = 36.

the 3rd on is correct

step-by-step explanation:

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

⇒

⇒ ⇒

factorizing, we get that:

  ⇒

then, the solutions are: or

nothing extraneous has been found!