Answer:
Step-by-step explanation:
Given
It takes 20 min and 30 min for a person and his friend to paint a wall individually i.e.
In 1 min they cover part and
part of wall respectively.
If the work together, 1 minute work is
Time required will be reciprocal of it
Answer: the percent of the students at this university are foreign = 30%
Step-by-step explanation:
Given: Probability that college students are foreign students who also smoke: P(S|F)=0.12
Probability that foreign college students smoke P(S∩F)=0.4
The probability that the students at this university are foreign :
[By conditional probability formula]
Hence, the percent of the students at this university are foreign = 30%