2
678
Seven of them.
18.53
Exactly 8 of them
15s-15 = 0
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
Prader-Willi Syndrome is neither dominant or recessive - it is simply a genetic anomaly that occurs at conception (it's not inherited - it just happens) where part of the 15th chromosome that should be present/active is missing. This occurs either because it is totally missing (known as deletion) or because the child gets 2 chromosome 15s from the mother (instead of 1 from mom and 1 from dad which is the way it should be) and therefore that part of chromosome 15 that should be active from the father is nonexistent (this is known as uniparental disomy, or UPD)
12 15s = 180.180 is an integer and not a fraction. However, it can be expressed in rational form as 180/1.