Several major automobile producers are competing to have the largest market share for sport utility vehicles (SUVs)

Question:

Several major automobile producers are competing to have the largest market share for sport utility vehicles (SUVs) in the coming quarter. A professional automobile market analyst assesses that the odds of General Motors not being the market leader are 6 to 1. The odds against Toyota and Ford having the largest market share in the coming quarter are similarly assessed to be 12 to 5 and 8 to 3, respectively.
a. Find the probability that General Motors will have the largest market share for SUVs in the coming quarter.
b. Find the probability that Toyota will have the largest market share for SUVs in the coming quarter.
c. Find the probability that Ford will have the largest market share for SUVs in the coming quarter.
d. Find the probability that some other automobile manufacturer will have the largest market share for SUVs in the coming quarter.