4 boys and 4 girls from a line with the boys and girls alternating. Find the number of ways of marking this line.

4 boys and 4 girls form a line with the boys and girls alternating . Find the number of ways of making this line .

2 boys and 2 girls are in Room X, and 1 boy and 3 girls are in Room Y. Specify the sample space for the experiment in which a room is selected and then a person.

In a class, there are 15 boys and 10 girls. How many ways a teacher can select 1 boy and 1 girl to represent the class at a seminar.

Five boy and five girls sit alternately around a round table. In how many ways can this be done?

10 students of class-X took part in a mathematics quiz. If the number of girls is 4 more than the number of noys then, find the number of boys and the number of girls who took part in the quiz.

Two thirds of students in a class are boys and rest girls. It is known that the probability of a girls. It is known that the probability of a girl getting a first grade is 0.85 and that of boys is 0.70. Find the probability that a student chosen at random will get first grade marks.