Question 154
All my Maths tests are out of the same total, and the average of my marks in the four tests so far is $75\%$. What percentage do I need in a fifth test so that my overall average will be $80\%$?
(A) $100$
(B) $90$
(C) $85$
(D) $80$
(E) $75$
(A) $100$
(B) $90$
(C) $85$
(D) $80$
(E) $75$