Answer:
n = 16
Step-by-step explanation:
Answer: 0.31
Step-by-step explanation:
Let A denotes the event that the students report drinking alcohol and B denotes the students report using some type of tobacco product .
Given : P(A) =0.84 ; P(B)=0.33 and P(A∪B)=0.86
We know that 
Then, the probability that the student both drunk alcohol and used tobacco in the past month is given by :-

Hence, the probability that the student both drunk alcohol and used tobacco in the past month = 0.31
This is a proportion problem that involves cross multiplication
3/5 = x/650
650 x 3 = 1950
1950/ 5 =390
Or you could have done 650 x .6 (which is the decimal form of 3/5) and got 390 as your answer
Answer: isosceles triangle!