6. The number of times that a person contracts a cold is a Poisson random variable with an average of 4 times/year. Suppose that a wonder.drug called Niagra can reduce the average number of colds contracted during a year to 3 times/year. Due to an aggressive marketing campaign, it is believed that 75% of the people have used Niagra last year. An individual had 2 colds last year, what is the probability that this individual used Niagra last year