X + y = 12 . . . . . . . . (1)
x - 3y = -30 . . . . . . . (2)
(1) - (2): 4y = 42
y = 10.5
P ( A ) = 0.45 - probability that the land has oil,
P ( B ) = 0.8 - probability that the test predicts it
P ( A ∩ B ) = P ( A ) · P ( B ) = 0.45 · 0.8 = 0.36
Answer: The probability that the land has oil and the test predicts it is 36 %.
The percentage of apples that are bad is 25%. This is because 25% of 24 is 6. I hope this helped!
Find AC using Pythagorean theorem
6^2 + 8^2 = AC^2
36 + 64 = AC^2
100 = AC^2
10 = AC
6+8+10 = 24
24/60 = 2/5
10/x = 2/5
50 = 2x
25 = x