Question

One month, Ruby worked 8 hours more than Isaac, and Svetlana worked 4 times as many hours as Ruby. Together they worked 112 hours. Find the number of hours each person worked.  

Answer 1

R=8+I
S=4R

R+I+S=112
R+R-8+4R=112
6R=120
R=20

So therefore, Ruby worked 20 hours, Svetlana worked 80 hours, and Isaac worked 12 hours.