Answer:
Mr Smith: 24
Mr Johnson: 20
Mrs Jones: 10
24+20+10=54
Explanation:
So I took a random number, and that number was 24.
I took 24 and put at as my testing in Smith's class.
If Mr. Smith had 24 students then, (x-4=Mr Johnson's class) Mr Johnson has 20 students, and half of that would be the amount of students in Mrs Jones class, so that equals 10.
J = Jones
Jo = Johnson
S = Smith
Finally S+Jo+J=54