Answer:
Monica = 48.50
Samuel = 24.25
Kara = 17.25
Explanation:
First you write equations as you are reading the text:
m = 2s ("Monica earned twice as much as Samuel")
s = k+7 ("Samual earned 7 more than Kara")
m = 48.50
Next, you convert these equations to solve for s and k respectively.
So, if m=2s, then s=m/2:
s = m/2 = 24.25
Likewise, if s=k+7, then k=s-7
k = s-7 = 17.25
The difference between greatest and least is 48.50 - 17.25 = 31.25