What is the full form of the acronym WWW?

A computer retail store has 15 personal computers in stock. A buyer wants to purchase 3 of them. Unknown to either the retail st

Dima020 [189]

Answer:

a. 1365 ways

b. Probability = 0.4096

c. Probability = 0.5904

Explanation:

Given

PCs = 15

Purchase = 3

Solving (a): Ways to select 4 computers out of 15, we make use of Combination formula as follows;

$^nC_r = \frac{n!}{(n-r)!r!}$

Where $n = 15\ and\ r = 4$

$^{15}C_4 = \frac{15!}{(15-4)!4!}$

$^{15}C_4 = \frac{15!}{11!4!}$

$^{15}C_4 = \frac{15 * 14 * 13 * 12 * 11!}{11! * 4 * 3 * 2 * 1}$

$^{15}C_4 = \frac{15 * 14 * 13 * 12}{4 * 3 * 2 * 1}$

$^{15}C_4 = \frac{32760}{24}$

$^{15}C_4 = 1365$

Hence, there are 1365 ways 

Solving (b): The probability that exactly 1 will be defective (from the selected 4)

First, we calculate the probability of a PC being defective (p) and probability of a PC not being defective (q)

From the given parameters; 3 out of 15 is detective;

So;

$p = 3/15$

$p = 0.2$

$q = 1 - p$

$q = 1 - 0.2$

$q = 0.8$

Solving further using binomial;

$(p + q)^n = p^n + ^nC_1p^{n-1}q + ^nC_2p^{n-2}q^2 + .....+q^n$

Where n = 4

For the probability that exactly 1 out of 4 will be defective, we make use of

$Probability = ^nC_3pq^3$

Substitute 4 for n, 0.2 for p and 0.8 for q

$Probability = ^4C_3 * 0.2 * 0.8^3$

$Probability = \frac{4!}{3!1!} * 0.2 * 0.8^3$

$Probability = 4 * 0.2 * 0.8^3$

$Probability = 0.4096$

Solving (c): Probability that at least one is defective;

In probability, opposite probability sums to 1;

Hence;

Probability that at least one is defective + Probability that at none is defective = 1

Probability that none is defective is calculated as thus;

$Probability = q^n$

Substitute 4 for n and 0.8 for q

$Probability = 0.8^4$

$Probability = 0.4096$

Substitute 0.4096 for Probability that at none is defective

Probability that at least one is defective + 0.4096= 1

Collect Like Terms

Probability = 1 - 0.4096

Probability = 0.5904

8 0

3 years ago

What security weaknesses/vulnerabilities exist in Wireless local area network device hardware and software?

AfilCa [17]

Answer:

Explanation:

There are many weaknesses/vulnerabilities, some of which are the following...

Default Network Hardware, many individuals will go out and buy a new router and install it in their home. These devices come with a preset configuration including a preset security password which is many times a default password used for every router of the same model. This can be easily obtained by anyone who can then access the network.

Access Point hacking, an experienced individual can use a packet sniffer to detect the SSID that is frequently sent from the router in order to create an access point to be able to access the network.

WEP encryption is another vulnerability. These are very low security passwords that can be cracked using different software in a short period of time.

These are some of many vulnerabilities that wireless local networks have, but there are also many precautions and security measures that can be taken to prevent them.

7 0

3 years ago

Write a program that uses an STL List of integers. a. The program will insert two integers, 5 and 6, at the end of the list. Nex

poizon [28]

Answer:

answer:

#include <iostream>

#include<list>

using namespace std;

bool Greater(int x) { return x>3; } int main() { list<int>l; /*Declare the list of integers*/ l.push_back(5); l.push_back(6); /*Insert 5 and 6 at the end of list*/ l.push_front(1); l.push_front(2); /*Insert 1 and 2 in front of the list*/ list<int>::iterator it = l.begin(); advance(it, 2); l.insert(it, 4); /*Insert 4 at position 3*/ for(list<int>::iterator i = l.begin();i != l.end();i++) cout<< *i << " "; /*Display the list*/ cout<<endl; l.erase(it); /*Delete the element 4 inserted at position 3*/ for(list<int>::iterator i = l.begin();i != l.end();i++) cout<< *i << " "; /*Display the list*/ cout<<endl;

l.remove_if(Greater); for(list<int>::iterator i = l.begin();i != l.end();i++) cout<< *i << " ";

/*Display the list*/

cout<<endl; return 0;

}

5 0

3 years ago

Read 2 more answers

Which of the following is primarily operated by a touchscreen?

LUCKY_DIMON [66]

Answer: The correct answer is Mobile device

Explanation:

A Mobile device is any portable equipment that can be easily connected to an internet. Example of mobile devices include; smart phones, palmtop, smart watch and other computer gadgets. The use of touchscreen for input or output on mobile devices can not be overemphasized. Mobile devices are handy and can be used for making work easy. As such, in order to effectively use mobile devices, touchscreen can be primarily used.

4 0

3 years ago

which application software allows you to compose written ideas on a computer? database, spreadsheet, word processor or graphics

Kazeer [188]

Word processor because it's more for writing

8 0

3 years ago