Suppose Set A contains 19 elements and Set B contains 69 elements. If the total number elements

Mathematics

1 answer:

balu736 [363]3 years ago

6 0

B u A = 48

B = 45

The part of set B not included in A is B - A∩B = 45 - 7 = 38

Since B u A = 48, A must have 48-38 = 10 elements (3 exclusive of B, 7 shared with B).

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Alternatively, the inclusion-exclusion principle may be used: A + B - (A ∩ B) = A u B

A + 45 - 7 = 48

A = 48 - 45 + 7

A = 10

NOTE that I'm using A and B to indicate the number of elements in each set, respectively.

More formally, one would write |A| and |B| to indicate the cardinality (number of elements) of the set.

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the teacher of a senior class needs to choose 4 members of the class to represent the school. if there are 10 seniors in the cla

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There are 10 seniors in the class, from which 4 should be chosen by the teacher. The order of the chosen students does not matter. This means that we speak of combinations. THe equation for calculating the number of possible combinations is:
C=N!/R!(N-R), where N is the total number of objects and R is the number of objects we select from the N
In our case, N=10, R=4.
C= 10!/4!*6!=10*9*8*7*6!/6!*4*3*2*1=10*9*8*7/24=5040/24=210
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4 years ago

8y + 7 = 6y - 3 Help solve

Alenkasestr [34]

Answer:

-5

Step-by-step explanation:

8y-6y=-3-7

2y=-10

y=-10÷2

y=-5

6 0