
William W. answered 09/19/19
Math and science made easy - learn from a retired engineer
Let D be the number of dreams you have that feature people you know and let n be the total number of dreams you have.
Then D = 3/4n or, since D is a function of n, we can write D(n) = 3/4n
Suppose you had 28 dreams last night, then n = 28.
So D(28) = 3/4(28) = 3*7 = 21 so you had 21 dreams featuring people you know