In a group of 20 students, 7 study both Art and Biology. 5 study Biology but not Art.
8 study neither subject.
Given that a randomly selected student studies Art, what is the probability the student studies Art and Biology?​

Step-by-step explanation:

A + B = 7

(Not A) + B = 5

(Not A) + (Not B) = 8

(Not A) = ((Not A) + B) + ((Not A) + (Not B) = 13

A = 20 - (Not A) = 7

Prob (A + B) given (A)

Prob (A+B) || A = (7/20) / (7/20)

Prob (A + B) || A = 1

why do wages differ across industries

step-by-step explanation :

micro economists are concerned with economics on an industry or individual firm basis.

macro economists are concerned with national and international level

x =±sqrt(1/3)

step-by-step explanation:

x+4/6x=1/x

multiply each side by 6x to get rid of the fractions

6x*(x+4/6x)=1/x*6x

distribute

6x^2 +4 = 6

subtract 4 from each side

6x^2 +4-4 = 6-4

6x^2 =2

divide by 6

6x^2/6 = 2/6

x^2 = 1/3

take the square root of each side

sqrt(x^2) = ±sqrt(1/3)

x =±sqrt(1/3)