Question:
If a sample of 2 hammer is selected
(a) find the probability that all in the sample are defective.
(b) find the probability that none in the sample are defective.
Answer:
a ![Pr = \frac{2}{110}](https://tex.z-dn.net/?f=Pr%20%3D%20%5Cfrac%7B2%7D%7B110%7D)
b ![Pr = \frac{72}{110}](https://tex.z-dn.net/?f=Pr%20%3D%20%5Cfrac%7B72%7D%7B110%7D)
Step-by-step explanation:
Given
--- hammers
--- selection
This will be treated as selection without replacement. So, 1 will be subtracted from subsequent probabilities
Solving (a): Probability that both selection are defective.
For two selections, the probability that all are defective is:
![Pr = P(D) * P(D)](https://tex.z-dn.net/?f=Pr%20%3D%20P%28D%29%20%2A%20P%28D%29)
![Pr = \frac{2}{11} * \frac{2-1}{11-1}](https://tex.z-dn.net/?f=Pr%20%3D%20%5Cfrac%7B2%7D%7B11%7D%20%2A%20%5Cfrac%7B2-1%7D%7B11-1%7D)
![Pr = \frac{2}{11} * \frac{1}{10}](https://tex.z-dn.net/?f=Pr%20%3D%20%5Cfrac%7B2%7D%7B11%7D%20%2A%20%5Cfrac%7B1%7D%7B10%7D)
![Pr = \frac{2}{110}](https://tex.z-dn.net/?f=Pr%20%3D%20%5Cfrac%7B2%7D%7B110%7D)
Solving (b): Probability that none are defective.
The probability that a selection is not defective is:
![P(D') = \frac{9}{11}](https://tex.z-dn.net/?f=P%28D%27%29%20%3D%20%5Cfrac%7B9%7D%7B11%7D)
For two selections, the probability that all are not defective is:
![Pr = P(D') * P(D')](https://tex.z-dn.net/?f=Pr%20%3D%20P%28D%27%29%20%2A%20P%28D%27%29)
![Pr = \frac{9}{11} * \frac{9-1}{11-1}](https://tex.z-dn.net/?f=Pr%20%3D%20%5Cfrac%7B9%7D%7B11%7D%20%2A%20%5Cfrac%7B9-1%7D%7B11-1%7D)
![Pr = \frac{9}{11} * \frac{8}{10}](https://tex.z-dn.net/?f=Pr%20%3D%20%5Cfrac%7B9%7D%7B11%7D%20%2A%20%5Cfrac%7B8%7D%7B10%7D)
![Pr = \frac{72}{110}](https://tex.z-dn.net/?f=Pr%20%3D%20%5Cfrac%7B72%7D%7B110%7D)
Correct question:
Every day Kim practice volleyball and clarinet each day she practices volleyball for 2.5 hours if after 8 days she practices both volleyball and the clarinet for a total of 36 hours how many hours per day did Kim practice clarinet.
Answer: 2 hours
Step-by-step explanation:
Everyday Kim practices volleyball and clarinet = v/ball + clarinet
Everyday volleyball practice = 2.5hours
That is clarinet(hours) + 2.5 hours of volleyball
After 8 day, total practice hours of both volleyball and clarinet equals 36 hours
The above information can be represented mathematically as thus:
Let h = hours per day of clarinet
8(h + 2.5) = 36
8h + 20 = 36
8h = 36 - 20
8h = 16
h = 16/8
h = 2
Answer:
24,840 cubic inches
Step-by-step explanation:
18 x 30 = 540 - rectangle house front surface area
540 + .5(30 x 10) = 690 - triangle house front surface area
690 x 36 = 24,840 - (rectangle + triangle surface area) x depth
4th quadrant is positive x (cos) and negative y (sin)
Use the Pythagorean Theorem to calculate the value of y (sin).
x² + y² = c²
5² + y² = 13²
25 + y² = 169
y² = 144
y = 12
Since the y-value is negative in the 4th quadrant, then y = -12
Step-by-step explanation: