What is the value of x? A 3 B 5 C 45 D 90

An electronics hobbyist has three electronic parts cabinets with two drawers each.

Andrews [41]

Answer:

a) 0.5 = 50% probability that an NPN transistor will be selected.

b) 0.3333 = 33.33% probability that it came from the cabinet that contains both types

c) 66.67% probability that it comes from the cabinet that contains only NPN transistors

Step-by-step explanation:

Conditional Probability

We use the conditional probability formula to solve this question. It is

$P(B|A) = \frac{P(A \cap B)}{P(A)}$

In which

P(B|A) is the probability of event B happening, given that A happened.

$P(A \cap B)$ is the probability of both A and B happening.

P(A) is the probability of A happening.

a) What is the probability that an NPN transistor will be selected?

1/3 probability that the first cabinet is chosen. This cabinet has two transistors, both of which are NPN, so 100% probability of selecting a NPN transistor.

1/3 probability that the second cabinet is chosen. This cabinet has two transistors, both of which are PNP, so 0% probability of selecting a NPN transistor.

1/3 probability that the second cabinet is chosen. This cabinet has two transistors, one of which is NPN, so 50% probability of selecting a NPN transistor.

So

$p = \frac{1}{3}*1 + \frac{1}{3}*0 + \frac{1}{3}*0.5 = \frac{1}{3} + \frac{1}{6} = \frac{2}{6} + \frac{1}{6} = \frac{3}{6} = 0.5$

0.5 = 50% probability that an NPN transistor will be selected.

b) Given that the hobbyist selects an NPN transistor, what is the probability that it came from the cabinet that contains both types?

Here we use the conditional probability formula.

Event A: NPN transistor

Event B: From the third cabinet.

50% probability that an NPN transistor will be selected, so $P(A) = 0.5$ .

1/6 probability that it is from the third cabinet and NPN, so $P(A \cap B) = \frac{1}{6}$

The desired probability is:

$P(B|A) = \frac{\frac{1}{6}}{0.5} = 0.3333$

0.3333 = 33.33% probability that it came from the cabinet that contains both types.

c) Given that an NPN transistor is selected what is the probability that it comes from the cabinet that contains only NPN transistors?

Either it comes from the cabinet with only NPN transistors, or it comes from the cabinet with both types of transistors. The sum of the probabilities of these outcomes is 100%. So

x + 33.33 = 100

x = 66.67

66.67% probability that it comes from the cabinet that contains only NPN transistors

6 0

3 years ago

A sphere with radius 16 m is cut by a plane that is 9 m below its center. what is the best approximation of the area of the circ

alexdok [17]

The complete question in the attached figure

we know that
the equation of a sphere is
(x-h)²+(y-k)²+(z-l)²=r²

let's assume that the center of the sphere is at the origin
so
(h,k,l)-------> (0,0,0)
for r=16 m
(x-h)²+(y-k)²+(z-l)²=r²--------> (x)²+(y)²+(z)²=16²

for z=9 m
(x)²+(y)²+(9)²=16²--------> (x)²+(y)²=256-81--------> (x)²+(y)²=175
the radius of the circle is r=√175 m
so the area of the circle A=pi*r²-----> A=pi*175-----> A=549.5 m²

the answer is
the area of the circle is 549.5 m²

6 0

3 years ago

Using slope formula find the slope of the line through the points 0,0 and 3,12 use the pencil and paper

sertanlavr [38]

Answer:

wouldn't it be 3,12.....................

7 0

2 years ago

Read 2 more answers

13.At the Finch School bake sale, donuts sell

aliina [53]

Answer:

c)

Step-by-step explanation:

create a system of equations:

d + m = 104

2d + 3m = 243

now use substitution method based on 'd = 104 - m'

2(104 - m) + 3m = 243

208 - 2m + 3m = 243

208 + m = 243

m = 35

So, 35 muffins and 69 donuts were sold.

This is 34 more donuts than muffins.

7 0

2 years ago

Solve for the missing angles and side lengths A= 20 degrees, b=4 a = 4.5 Find the measure of C

Reil [10]

Answer:

Its 142

Step-by-step explanation:

Theres a website called triangle calculator and you put in three things wether its SSA or ASA or whatever and it gives you all the measurements. Good luck on your quizzes and tests :)

6 0

2 years ago