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:
There are 15 girls.
Step-by-step explanation:
The ratio is 4:3, meaning there are 7 parts.
4 parts= 20 (Boys)
This means 1 part is 20 divided by 4.
1 part= 5
3 parts= Amount of girls.
3 x 5 = 15.
There are 15 girls.
Answer:
Obi's age is 18 and Oba's age is 9
Step-by-step explanation:
Let Obi's age be x and Oba's age be y
<u><em>Condition 1:</em></u>
x = 2y -----------(1)
<u><em>Condition 2:</em></u>
(x-4) = 3(y-4)
=> x -4 = 3y-12
=> x - 3y = -9 -----(2)
<u><em>Putting eq (1) in (2)</em></u>
2y - 3y = -9
=> -y = -9
=> y = 9
Now,
x = 2y
=> x = 2(9)
=> x= 18
Answer:
Answer: 3
Step-by-step explanation:
Use BODMAS
<u>Step 1: Open bracket (1 2/5 +3.5÷1 1/4 )</u>
<em>Convert mixed fractions into improper fractions</em>
7/5 + 3.5 ÷ 5/4
<em>Divide 3.5 by 5/4</em>
7/5 + 2.8 = 4.2
<u>Step 2: Carry out all divisions</u>
<em>Convert mixed fraction into improper fractions</em>
4.2 ÷2 2/5 +3.4÷2 1 /8 −0.35
4.2 ÷ 12/5 + 3.4 ÷ 17/8 - 0.35
1.75 + 1.6 - 0.35
<u>Step 3: Solve</u>
1.75 + 1.6 - 0.35
3.35 - 0.35
Answer = 3
