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
Mars2501 [29]
3 years ago
10

A shop has 8 different types of postcards and at least 13 of each type. how many selections of 12 postcards are there if

Mathematics
1 answer:
Zolol [24]3 years ago
4 0

Answer:

Answered

Step-by-step explanation:

It is a combbinatorics problem. let's think as we need to do 8 partitions  

of these 13 to separate the postcards of different types. So The number of

partitions of n=13 into r=8 terms counting 0's as terms as  C(n+r-1,r-1)​.

(a)

Here n=13 and r=8, put it in the above formula so we get C(13+8-1,8-1)= C(20,7)= 77520 selections.

b).

Here, either (i) we can choose none of type I or (ii) we choose one of type I

Case(i): r=7, n=12 (Here we have only 7 types to choose from​)

Case(ii): r=7, n=11 (Here we have only 11 cards to choose and only 7 types to choose them from)​

Case (i) + Case(ii) = ,C(12+7-1,7-1) + C(11+7-1,7-1) = C(18,6) + (17,6) = 18564+12376 = 30940 selections.

You might be interested in
If a pond is 6m by 15m, will 40m of fencing will be enough to fenced a pond
olchik [2.2K]

6m + 6m + 15m + 15m = 42m

no 40m will not be enough

8 0
3 years ago
3x+5=19-4x<br>What does x equal?​
alexandr1967 [171]

Answer:

x=2

Step-by-step explanation:

x=2 in the equation 3x+5=19-4x

8 0
2 years ago
The cost of making a cheese cake is RM45. In
mars1129 [50]

Answer:

CHEESE

Step-by-step explanation:

SKDMALSD

3 0
2 years ago
Evaluate the function f(x)=3x-7if x=6
notka56 [123]

Answer:

if x=6, then f(6)=11

8 0
3 years ago
Read 2 more answers
Jake and Erica were solving a system of equations. They both noticed that the two lines had the same slope. Jake said that becau
cluponka [151]
The correct answer is option A. Erica is correct in saying that the two lines are not necessarily the same and we should also look at the y-intercepts before determining how many solutions there were. <span>Two lines with equal slopes could be the same line, but only if they have the same y-intercept.</span>
3 0
2 years ago
Read 2 more answers
Other questions:
  • Help me pls and I need the answer fast
    14·1 answer
  • Any idea ? I need help
    15·2 answers
  • Which expression is a perfect cube? x to the 8th power y to the 24th power m to the 28th power s to the 64th power
    8·1 answer
  • What degree rotation mapped R(5,-6) to R’(6,5)?
    15·1 answer
  • Solve the following system of equations and show all work.<br><br> y = 2x2<br> y = −3x −1
    14·1 answer
  • One - third the difference between 3/4 and 1/5
    11·2 answers
  • Plot the following and their opposites on the number line.
    11·1 answer
  • Not graded help please
    6·1 answer
  • GAME SHOW GET READY... WHOEVER ANSWERS CORRECT GETS BRAINLIST
    11·1 answer
  • Sorry before it didn't came
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!