Question

The set O represents the maximum temperatures, in degrees Fahrenheit, recorded in the city of Orlando in a year.

O = {71, 71, 72, 73, 77, 77, 79, 83, 84, 89, 90, 91}

The set T represents the maximum temperatures, in degrees Fahrenheit, recorded in the city of Tampa in a year.

T = {70, 72, 76, 78, 81, 81, 84, 86, 86, 89, 90, 90}

How many elements are in the set O ∪ T?

24

15

5

4

Answer 1

The ∪ symbol means union, which means every elements in both sets. Note that there's a catch: the same number will not appear twice in this new union set. For example if we have:
A = {1, 3, 4, 5, 6, 7}
and
B = {1, 4, 8, 9, 15}

Then A ∪ B will be {1, 3, 4, 5, 6, 7, 8, 9, 15}.

Answer 2

so ?

Answer 3

So, you put every element from both sets in a new set, then eliminate any duplicates in this new set.

Answer 4

still lost

Answer 5

it helps if we know what your lost on ....

Answer 6

@amistre64 Ninja'd :P

Answer 7

the whole thing

Answer 8

write down all the elements of each set together

each value only needs to be accounted for one time, and one time only; so duplicates can be erased. what is left is the number of elements in the set for the solution

Answer 9

@kwashondap An example:

A = {1, 2, 3}
B = {2, 4, 5}
Find A ∪ B.

Remember that ∪ means union, which basically boils down to putting the two sets together, then eliminate the duplicates.

Firstly put them together: O = {1, 2, 2, 3, 4, 5}
Now that ∪ means no duplicates, so eliminate the extra 2 and you'll get the final set: A ∪ B = {1, 2, 3, 4, 5}.

Answer 10

O = {71, 71, 72, 73, 77, 77, 79, 83, 84, 89, 90, 91}
T = {70, 72, 76, 78, 81, 81, 84, 86, 86, 89, 90, 90}

lets go ahead and clean out the duplicates from each set

O = {71, 72, 73, 77, 79, 83, 84, 89, 90, 91}
T = {70, 72, 76, 78, 81, 84, 86, 89, 90}

now lets clean out the duplicates that each set has in common

O = {71, 73, 77, 79, 83, 84, 89, 90, 91}
T = {70, 72, 76, 78, 81, 86}

now that there are no longer any duplicate values, how many elements are left?