In a cer tain 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 girl.

In a class having 60% boys, 5% of the boys and 10% of the girls have an I.Q. of more than 150. A student is selected at random and found to have an I.Q. of more than 150. Find the probability that the selected student is a boy.

In a class of 25 students with roll numbers 1 to 25, a student is picked up at random to answer a question. Find the probability that the roll number of the Selected student is either a multiple of 5 or of 7.

A class consists of 10 boys and 8 girls. Three students are selected at random. Find the probability that the selected group has : all girls.

Marks obtained by 2500 students are shown in the following table: A student is selected at random. Find the probability that : he scores less than 60% marks.

A class consists of 10 boys and 8 girls. Three students are selected at random. Find the probability that the selected group has : 2 boys and 1 girl.

40% students of a college reside in hostel and the remaining reside outside. At the end of the year, 50% of the hostlers got A grade while from outside students, 30% got A grade in the examination. At the end of the year, a student of the college was chosen at random and was found to have gotten A grade. What is the probability that the selected student was a hostler ?

A class consists of 10 boys and 8 girls. Three students are selected at random. Find the probability that the selected group has : all Boys.

20 % of 25 students in a class are boys.How many girls are in the class?

Marks obtained by 2500 students are shown in the following table: A student is selected at random. Find the probability that : he scores more than 80% marks.