In a certain college, 4% of boys and 1% of girls are taller than 1.75 metres. Furthermore, 60% of the students in the college are girls. A student is selected at random from the college and is found to be taller than 1.75 metres. Find the probability that the selected student is a girl.

In a class, 5% of the boys and 10% of the girls have an IQ of more than 150. In this class 60% of the students are boys. If a student is selected at random and found to have an IQ of more than 150, find the probability that the student is a boy.

A class has 20 girls and 16 boys. One student is selected at random. Find the probability that the student is a girl.

In a class of 50 students, 20 are boys and rest are girls. A student is selected at random. Find the probability of selecting a boy.

A class consists of 50 students out of which there are 10 girls. In the class 2 girls and 5 boys are rank holders in an examination. If a student is selected at random from the class and is found to be a rank holder, what is the probability that the student selected is a girl?

A class has 12 boys and 4 girls. If three students are selected at random from the class, what is the probability that all will be boys?

In a group of students , there are 3 boys and 3 girls . Four students are to be selected at random from the group . Find the probability that either 3 boys and 1 girl or 3 girls and 1 boy are selected .

Of the students in a college, it is known that 60% reside in a hostel and 40% do not reside in hostel. Previous year results report that 30% of students residing in hostel attain A grade and 20% of one’s not residing in hostel attain A grade in their annual examination. At the end of the year, one students is chosen at random from the college and he has an A grade. What is the probability that the selected student is a hosteller?

There are 60% students in Maths and 30% in Biology. If 10% students are in both subjects. Find the probability that a randomly selected student has Maths or Biology.

Out of 9 outstanding students in a college, there are 4 boys and 5 girls. A team of four students is to be selected for a quiz programme. Find the probability that two are boys and two are girls.

Of all the students in a school, it is known that 30% have 100% attendance and 70% students are irregular. Previous year results report that 70% of all students who have 100% attendance attain A grade and 10% irregular students attain A grade in their annual examination. At the end of the year, one student is chosen at random from the school and he was found to have an A grade. What is the probability that the student has 100% attendance ? Is regularity required in school ? Justify your answer.