Question

please explain why. In a competition of 50 professional ballroom dancers, 22 compete in the fox-trot competition, 18 compete in the tango competition, and 6 compete in both the fox-trot and tango competitions. How many dancers compete in the fox-trot or tango competitions?

Answer 1

22+18-6=34

Explanation:

Let's call F the set of dancers who dance fox-trot (not necessarily just that, they may also dance something else, what's important is that, amongst other things, they also dance fox-trot), and T the set of dancers who dance tango.

We know that F has 22 elements, T has 18, and the intersection of sets F and T (e. g. those who dance both tango and fox trot) has 6 ones.

Now, let's take a further look at how those sets are made up.

Let's take set F, for example. In it, there is some number of dancers who dance only fox trot, and some others who dance both fox trot and tango.

Similarly, set T is made up of those who dance only tango and those who dance both fix trot and tango.

Therefore, if we were to add those sets together, we would get the number of those who only dance tango, plus the number of those who only dance fox trot, plus two times the number of those who dance both.

We can make up for that, and get the desired result, by subtracting the union of sets F and T from their sum.

Hope this was a clear explanation :)

Answer 2

Answer: 34 of them do

Step-by-step explanation: It says that 22 of them compete in the fox-trot and then it says 18 compete in the tango and then at the end it says that 6 compete in both. Based on what that said I can confirm that it's 36 because the question they want us to answer is only the ones who do fox-trot or tango not both

Hope this helps :)