Step-by-step explanation:
ratio =4:1
total= 4+1 =5
1/5 × 52= 10.4 years
Answer:
The first shape is triangle; area of a triangle = 1/2*b*h
= 1/2*7*3
= 1/2*21
= 21/2
= 10.5
The second shape is rectangle; area of rectangle = l*b
= 7*3
= 21
Total area:
10.5+21
= 31.5
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