Answer:
Option A 0.1698
Step-by-step explanation:
Given that Jason has a chance for getting oil as 45%
THe kit he buys show accurate result with 80% probability
Let A1- Event that the land has oil
A2 - Event that the land has no oil
B- The test gives negative result
A1 and A2 are mutually exclusive and exhaustive
P(A1) = 0.45 and P(A2) =0.55
Hence we can use Baye theorem
Then P(B) = P(A1B)+P(A2B)=
Reqd prob =P(A1/B) =

Step-by-step explanation:
Ethan sold 2/3 gallon of lemonade.
Kayla sold some lemonade too.
Together they sold 1 1/4 gallons.
Subtract 2/3 from 1 1/4 as follows :

So, Kayla sold 7/12 gallons of lemonade.
As 2/3 is more than 7/12, it means Ethan sold more lemonade.

It means Eathn sold 1/12 more lemonade.
The answer is 1/20 or 0.05
If you have at least as many equations as your have unknown variables, the 'system' is solvable (unless the equations are copies of eachother).
In this case, isolate one letter and plug it in the other. I'm going for the 2a in the bottom one (it doesn't matter)
2a - 4b = 12 => (divide by two and move the b's to the other side)
a = 6 + 2b. (plug this one into the top equation)
4(6+2b) + 6b = 10 => 24+8b+6b = 10 => 24 + 14b = 10 => 14b = -14 => b=-1
a = 6 + -2 = 4.
So a=4 and b=-1.