First, we determine the speed of the ferry by dividing the distance by the time it took to cover that certain distance.
speed = (1/6) / (3/7)
speed = 7/18
Then, the distance it will travel for an hour is calculated through the procedure below.
distance = (7/18hour) x (1 hour)
distance = 7/18
Therefore, after an hour, the ferry will be able to travel 7/18 of the distance between two ports.
So,
The probability of the man having diabetes is 0.6 or 60%. Because we are figuring the probability BEFORE the test is taken that he has the disease, we can disregard the test and its accuracy rate. That rate is 60%, the probability of him having diabetes.
The correct option is D.
I think it would have to equal a fraction being -4/3