the four sided spinner has 4 sides thus 4 different values

lets denote the sides of the spinner with A,B,C and D

one outcome is when at the first spin falls A and the second spin falls B

the total number of outcomes will be the number of all pairs from the set {A, B, C, D} - this is when the order of the outcomes matters

that is Variations of class 2 from 4 element V(4,2) = 2^4 = 16

there are 16 possible outcomes

we can also write them down

AA, AB, AC, AD

BA, BB, BC, BD

CA, CB, CC, CD

DA, DB, DC, DD

if the order of the outcomes is not important (outcome A,B is the same as outcome B,A)than the number of possible outcomes will be 2-combinations of 4 elements with repetition that is 10

(4 + 2 -1)!/(2!(4 + 2 - 1 -2)!) = 5!/(2!3!) = 10