One month, Ruby worked 4 hours more than Isaac, and Svetlana worked 4 times as many hours as Ruby. Together they worked 104 hours. Find the number of hours each person worked.

Let Isaac = x

Ruby = x + 4

Svetlana = 4 (x + 4)

Together they worked 104 hours, so ...

x + x + 4 + 4 (x + 4) = 104

x + x + 4 + 4x + 16 = 104

6x + 20 = 104

6x = 84

x = 84/6 = 14

Isaac worked x = 14 hours

Ruby worked x + 4 = 18 hours

Svetlana worked 4 (x + 4) = 4*18 = 72 hours

Check your answers ...

72 + 18 + 14 = 104

104 = 104 it checks!