LinaNY wrote:

Bunuel,

Could you please give an example of a problem where we would use Total= only A+ only B + both. Why aren't we using this formula in this problem?

thanks

It depends on what information you have with you.

If you know the values of TOTAL, ONLY A and ONLY B and you need to calculate the value of BOTH, then you can use the formula:

Total= only A+ only B + both

But if you don't know the values of ONLY A and ONLY B (like in this case where we are able to deduce the values of A and B but not of ONLY A and ONLY B), the we should use the following formula:

Total= A+ B - BOTH.

So use of formula varies depending on the information available.

I hope I have addressed your query

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