678
Seven of them.
18.53
15s-15 = 0
2
The coordinates 15S, 75W represent a location in Peru, in or near Poroma on the Panamericana Sur.
Two 15s' equals 30.
12r - 15s - r + 3s = 11r -12s
15s=58.5 s=58.5/15 s =3.9
45
12 15s = 180.180 is an integer and not a fraction. However, it can be expressed in rational form as 180/1.
30