WAEC - Mathematics (2017 - No. 43)
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.
\(\frac{2}{9}\)
\(\frac{4}{9}\)
\(\frac{5}{9}\)
\(\frac{7}{9}\)
ব্যাখ্যা
28 - x + x + 25 - x = 45
53 - x = 45
x = 53 - 45
x = 8
chemistry only = 28 - 8
= 20
Probability = \(\frac{20}{45}\)
= \(\frac{4}{9}\)