Question 675775
{{{drawing( 600, 600, -5, 15, -5, 15,
  grid( 0 ),locate(1,3-.2,"A"),locate(9,3-.2,"B"),locate(3,3-.2,"Aintersect B=41"),locate(5,-3-.2,"A U B"),
 
  circle(2.5, 2.5, 5),
  green( circle( 7.5, 2.5, 5 ) )
  
)}}}


n(A) = 102, n(A u B) = 140, and n(A ∩ B) = 41, find n(B).

n{{{B}}}=n(A u B)-(n(A)-n(A ∩ B))

n{{{B=140-(102-41)}}}

n{{{B=140-61}}}

n{{{B=79}}}