In an examination, Kofi scored x% in Physics, 50% in Chemistry and 70% in Biology. If his mean score for the three subjects was 55%, find x
-
A.
40 -
B.
45 -
C.
55 -
D.
60
Correct Answer: Option B
Explanation
(frac{x + 50 + 70}{3} = 55)
x + 120 = 3(55)
x + 120 = 165
= 165 – 120
x = 45%