Question

let the universal set, s, have 139 elements. a and b are subsets of s. set a contains 42 elements and set b contains 94 elements. if sets a and b have 26 elements in common, how many elements are in a but not in b?
answer = elements
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Explanation:

Step1: Identify relevant values

Total elements in $A$: $n(A)=42$; Common elements: $n(A\cap B)=26$

Step2: Calculate elements in A only

Subtract common elements from total A elements.
$n(A - B) = n(A) - n(A\cap B)$
$n(A - B) = 42 - 26$

Answer:

16 elements