14 million bacteria were present when the antibiotic was first introduced.
Answer:
a) 0.06 = 6% probability that a person has both type O blood and the Rh- factor.
b) 0.94 = 94% probability that a person does NOT have both type O blood and the Rh- factor.
Step-by-step explanation:
I am going to solve this question treating these events as Venn probabilities.
I am going to say that:
Event A: Person has type A blood.
Event B: Person has Rh- factor.
43% of people have type O blood
This means that 
15% of people have Rh- factor
This means that 
52% of people have type O or Rh- factor.
This means that 
a. Find the probability that a person has both type O blood and the Rh- factor.
This is

With what we have

0.06 = 6% probability that a person has both type O blood and the Rh- factor.
b. Find the probability that a person does NOT have both type O blood and the Rh- factor.
1 - 0.06 = 0.94
0.94 = 94% probability that a person does NOT have both type O blood and the Rh- factor.
Answer:
The length of the longer ladder is 35 ft
Step-by-step explanation:
Please check the attachment for a diagrammatic representation of the problem
We want to calculate the length of the longer ladder ;
We make reference to the diagram
Since the two right triangles formed are similar. the ratios of their sides are equal;
Thus;
20/15 = 28/x + 15
20(x + 15) = 15(28)
20x + 300 = 420
20x = 420-300
20x = 120
x = 120/20
x = 6
So we want to calculate the hypotenuse of a right triangle with other sides 28ft and 21 ft
To do this, we use the Pythagoras’ theorem which states that square of the hypotenuse equals the sum of the squares of the two other sides
Let the hypotenuse be marked x
x^2 = 28^2 + 21^2
x^2 = 1,225
x = √1225
x = 35 ft
Answer: Jennas will nedd 351 inches of ribbon to make 9 bows
Step-by-step explanation:multiply 39 and 9