10 people who build at the same rate can frame a house in 6 days. That means it will take one person days to finish the house.
Which means that it will take 4 people days to finish the house.
So, the fractional part of the house 4 people can frame in 3 days will be
Thus, Option D is the correct answer.
The results of the survey are shown in the table.
It's required to calculate the following probabilities:
a) A customer is neutral
The row labeled as 'Neutral' has a total of 79 customers out of 367 in total.
The required probability is:
b) A customer is a walk-in
The first column labeled as 'Walk-in' has a total of 106 customers out of 367. The required probability is
c) A customer is dissatisfied and a walk-in.
We have to cross the row Dissatisfied with the column Walk-in. The number of customers that have both categories is 22 out of 367.
The required probability is:
d) A customer is very satisfied given he saw a TV ad.
This is a conditional probability, where the total is 111 because is the given condition. The customers that have both characteristics are 33, thus the required probability is:
e) A customer is satisfied or referred.
Total satisfied = 139
Total referred = 150
With both features = 62
Total customers with one or both features: 139 + 150 - 62 = 227
We have to subtract the common feature because it was counted twice.
The required probability is:
