A, B, C are circular regions as shown below. There are 7 items in C and there are 20 items in A but 10 of those items are not in B. How many items are in B that are not in C
Answer:
3 items are in B that are not in C
Step-by-step explanation:
a: only in a, not count those in b or c
b: only in b, not count those in a or c
c: only in c, not count those in a or b
A = a + b + c = 20
c = 7
a + b = 20 - 7 = 13
10 not in b, of course not in c ∴ a = 10
b = 13 -10 = 3