Question

During one month, Jack, Bob, and Jerry earned a total of $115. If Bob earned twice as much as Jack, and Jerry earned $15 more than Jack, how much did each earn?

Answer 1

Jack - $ x

Bob - $ y

Jerry - $ z

x+y+z=115 (1)

y=2x (2)

z=x+15 (3)

We can substitute (2) and (3) into (1).

x+2x+x+15=115

4x=115-15

4x=100

x=$25 (Jack)

y=2x=2*25=50

y=$50 (Bob)

z=x+15=25+15=40

z=$40 (Jerry)