C = {2, 4, 6, 8, 10, 12, 14, 16} and D = {numbers divisible by 4 from 1 to 20}, what is C ∩ D?

Question

aroub · Answer

Do you know what does ∩ mean?

anonymous · Answer

no

aroub · Answer

It means 'intersection' you put all the similar numbers in set C & D like this : 

C = {2, 4, 6, 8, 10, 12, 14, 16} 
D=  {4 8 12 16 20}

What similar numbers do you find between the two sets?

aroub · Answer

You put it as: 

C ∩ D= {                    }         

You put the similar numbers between C & D in the set ^ & you're done :)

aroub · Answer

let me give you an example, I can see 4 in C & D so I'll put it in the set C ∩ D= { 4,                    }   
what else do you see?

aroub · Answer

(ok I know... I'm sorry I don't explain very well :(  but do you get it somehow? )