Answer:
Step-by-step explanation:
Let's call Joseph "J", Mark "M", and Kevin "K" for ease. We need a system of equations to solve this, 3 equations for 3 unknowns. The first equation is
J + M = 230. The second equation is
J + K = 130. The third equation is
M = 3K. Sub that 3K into the first equation and get
J + 3K = 230. Now take th second equation and solve it for J:
J = 130 - K. Now sub 130 - K into the re-written first equation to get a whole new equation in terms of K only:
130 - K + 3K = 230 and
2K = 100 so
K = 50
Kevin has $50
