In a class of 45 students, 28 offer chemistry and 25 offer Biology. If each student offers at least one of the two subjects, calculate the probability that a student selected at random from the class the class offers chemistry only.
-
A.
(frac{2}{9}) -
B.
(frac{4}{9}) -
C.
(frac{5}{9}) -
D.
(frac{7}{9})
Correct Answer: Option B
Explanation
28 – x + x + 25 – x = 45
53 – x = 45
x = 53 – 45
x = 8
chemistry only = 28 – 8
= 20
Probability = (frac{20}{45})
= (frac{4}{9})