In a class, 120 students speak English or French or both. 70 speak English and 55 speak french. how many speak English but not French?

Answer 1

120 - (70 + 55) = ?

Answer 2

n(E n F)= n(E)+n(F) - n(£)
=(70+55) - 120
=5
n(E n F')=n(E) - n(E n F)
=70-5
=65