Help with sets

Question

Help with sets

anonymous · Answer

please wait while i attach the question

amistre64 · Answer

twiddlin thumbs

anonymous · Answer

it's not letting me so i'll have to type it..

amistre64 · Answer

ill be around ....

anonymous · Answer

Use an appropriate formula
Find the value of n(B) if n(A)=20, n(AnB)=6, and n(AUB)=30

amistre64 · Answer

and what are your thoughts baout a solution?

anonymous · Answer

n(AUB) = n(A) + n(B) - n(AnB)

amistre64 · Answer

seems good to me

anonymous · Answer

30 = 20 + n(B) - 6 and solve for n(B)
but my concern is that it asked me to use a forumula

amistre64 · Answer

you used a formula

amistre64 · Answer

you used an appropriate formula too, it had all the required parts

anonymous · Answer

well i made up one, is that what is was asking? cause i wasnt sure if it was asking for my to make a formula out of it or use an already existing forumla to solve the question

amistre64 · Answer

well, the formula you made up is a formula that is actually used ... not sure what you mean by made up

anonymous · Answer

well i mean, I used the information given to me and just made an equation based on their relation but any how I was just confirming thx!! i have another question i need help with if you dont mind :)