This is a true statement.
Consider two events A and B. We say they are complementary if P(A)+P(B) = 1
This means that either event A or event B must happen, since the "1" represents 100% probability. Having a probability of 100% means absolute certainty.
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Example:
A = the event it rains
B = the event it does not rain
P(A) = 0.30 = 30% chance of rain
P(B) = 0.70 = 70% chance it does not rain
P(A)+P(B) = 0.30+0.70 = 1
So this shows the two events are complementary.
Answer:
Answer is d - x = 
Step-by-step explanation:
Step 1: Add 'z' to both sides
4x -z (+z) = y + z
4x = y + z
Step 2: To solve for x, divide both sides by 4
= 
x = 
Answer: 30 goldfish
Step-by-step explanation: Bruce has 18 goldfish. If Isabelle has 5 times as many goldfish as Bruce she will have 18*5=90 goldfish. If Arlene has 1/3 times as many goldfish as Isabelle she will have 90/3=30 goldfish.
Answer:
0.45
Step-by-step explanation:
Well the multiplication part is the same .Its in the ordering it has to be(ex: 42 times 35) but it has to be placed vertically .For the second number multiply to the right then the left .Repeat .Then you got your answer using 2 digits similar to regular multiplication partial products .Hope this helped !!