We can simplify across between the 5 and the 50 and also between the 42 and the 3.
37 is the answer of this. Hope this helps :)
Answer:
A intersection B = ( elements which are common in both)
= ( 2,4,7,19)
A union B = ( all the elements which are either in A or in B).
= ( 2, 4, 7 , 13, 14, 19, 20 , 3, 5, 6, 10,11, 12 , 15,17 , 18 , 19 )