Answer:
Hence, the probability of a Negative test is
.
Step-by-step explanation:
(a)
Let
Drug user and
Test positive
Probability of drug users 


(b)
Find the Probability of a Negative test,





Answer:
89 km/hr
Step-by-step explanation:
Distance = Rate(speed) × Time
D = R × T
T = 4 hours
One car's rate is 12 kilometers per hour less than the other's.
Hence:
First's car's rate = r × 4 = 4r
Second car's distance = (r + 12) × 4 = 4r + 48
4r + 4r + 48 = 760
8r + 48 = 760
8r = 760 - 48
8r = 712
r = 712/8
r = 89 km/hr
The rate of the slower car is 89 km/hr
60£
Peter = 2 Angard
Angard = 3 Nick
Peter = 2 Angard = 6 Nick
Angard = 3 Nick
Nick = 1 Nick
6+3+1=10 Nick
60£/10 = 6£
Nick = 6£
Angvard = 3 Nick = 6£*(3) = 18£
Peter = 6 Nick = 6£*(6) = 36£
(prove: 6+18+36=60£)
I will go about solving this using the elimination method.
First, convert the equations.
10x + y = -20
4x + y = -12
Second, find the easiest variable to get rid of and get rid of it! (In this case, y) We will subtract to get rid of y.
6x = -8
Third, you want to solve the equation.
6x = -8 (divide by 6)
x =

Fourth, solve for y by inserting the answer for x into one of the equations.
10(

) + y = -20

+ y = -20 (subtract

)
y =

The solution for this system of equations is (

,

).