1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
scoray [572]
3 years ago
8

Suppose that there are 15 antennas in a store, of which 3 are defective. Assume all the defectives and all the functional antenn

as are indistinguishable. If we lay all the antennas down in a row, how many linear orderings are there in which no two defectives are consecutive?
Mathematics
1 answer:
ohaa [14]3 years ago
7 0

Answer:

Step-by-step explanation:

Total number of antenna is 15

Defective antenna is 3

The functional antenna is 15-3=12.

Now, if no two defectives are to be consecutive, then the spaces between the functional antennas must each contain at most one defective antenna.

So,

We line up the 13 good ones, and see where the bad one will fits in

__G __ G __ G __ G __ G __G __ G __ G __ G __ G __ G __ G __G __

Each of the places where there's a line is an available spot for one (and no more than one!) bad antenna.

Then,

There are 14 spot available for the defective and there are 3 defective, so the arrange will be combinational arrangement

ⁿCr= n!/(n-r)!r!

The number of arrangement is

14C3=14!/(14-3)!3!

14C3=14×13×12×11!/11!×3×2

14C3=14×13×12/6

14C3=364ways

You might be interested in
How do I andser this. I’m stuck
Mars2501 [29]
A= 3:5
b= 12:20
c= yes because 3” 3+2=5 n in the beginning of the problem it said end of season
8 0
3 years ago
John joined a gym for 6 months. He pays 20$ per month plus a membership fee. If his bill is 150$, what was the membership fee?
Jlenok [28]

Answer:

Step-by-step explanation:

If he's been at the gym for 6 months, and he is charged $20 each month, then he has paid $120 dollars, not counting his membership fee. His total bill is $150.

150-120= $30

His membership fee was $30.

Hope this helps!

Mark Brainliest plz!

3 0
3 years ago
Read 2 more answers
Tina sends 12 text messages each day in June. A mobile phone company offers two packages. Package A: The first 100 texts each mo
Mnenie [13.5K]

Two options are given to Tina. We find how much she pays for each option, and the one in which she pays less offers the better value.

Tina sends 12 text messages each day in June

June has 30 days, so in June, Tina sent 12*30 = 360 text messages.

Package A:

First 100 messages cost 3p, the next 100 cost $2 and after that each costs $1.

She sends 360 messages, with:

The first 100 costing 3p.

The next 100 costing 2p.

The final 360 - 200 = 160 costing 1p.

She pays:

100*3 + 100*2 + 160*1 = 660

Package B:

2p for each message, 360 messages, so:

360*2p = 720p.

Which package is better?

Package A costs less, thus, it offers her the better value for money in 30 days.

Another example of a problem in which a person has to choose between two packages is given in brainly.com/question/10693932

6 0
3 years ago
10) in a school there are 1500 students. if 60% are boys, find the numbers of boys.​
Debora [2.8K]

Answer:

900

Step-by-step explanation:

.6 * 1500

4 0
2 years ago
Read 2 more answers
Factor out this expression: 4x² - 9y2
Marta_Voda [28]

Answer:

(2x+3y)(2x-3y)

Step-by-step explanation:

a² - b² = (a + b)(a - b)

4x² - 9y²

= (2x)² - (3y)²

= (2x + 3y)(2x - 3y)

5 0
4 years ago
Other questions:
  • The complement of every acute angle must be
    12·1 answer
  • Thirty-one is three more than twice a number divided by three
    5·2 answers
  • David currently has $270 in his bank account and
    9·2 answers
  • Maths<br>-|-30-(10-20)|-|5-(10-15)|=?<br>If someone helped me , I would be grateful​
    15·1 answer
  • A 16-ft. board is to be cut into three pieces. Two of the pieces must be 4 feet shorter than the third piece. How long should ea
    7·1 answer
  • What is 1/2x-3y-4=0 written in standard form
    14·1 answer
  • Im giving brainlyest to first CORECT answer and 30points QUICKKKKKK
    8·1 answer
  • Give the first 4 terms of the arithmetic sequence for which a(1) = -8 and d = 3.
    9·1 answer
  • A computer tracking chip company wants to test their chips. They marked 32 birds by attaching computer chips to their legs. Late
    7·1 answer
  • James is following this recipe to make flapjacks.
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!