So you will want to form a few equations. The first one is:
C+R+B=133
Then you will want to form an equation for Bob:
B=3R
Then, another for Carmen
C=R+8
Knowing this information, you can plug each in, solving for R.
R+8+R+3R=133 Now Solve
5R+8=133 Subtract 8 from both sides
5R=125 Divide 5 from both sides
R=25 Now substitute R in for Carmen and Bob equations.
R=25 Reuben has $25
C=8+25 Add
C=33 Carmen has $33
B=3(25) Multiply
B=75 Bob has $75
Check answer:
25+33+75=133
133=133
I hope this helps!