In a function, girls were allowed to wear only red, blue or black dress. If 15 girls were wearing red, 10 girls were wearing blue and 20 girls were wearing black, then the probability that a girl selected at random was not wearing black dress is:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → \(\frac{5}{9}\)
Every girl is equally likely to be chosen, so the probability is the number of girls not in black divided by the total number of girls.
Total girls \(=15+10+20=45\)
Girls not in black (red or blue) \(=15+10=25\)
Probability \(\displaystyle =\frac{25}{45}=\frac{5}{9}\)