5 girls and 10 boys sit at random in a row having 15 chairs numbered as 1 to 15. Find the probability that end seats are occupied by the girls and between any two girls odd numbers of boys sit.

Six boys and six girls sit in a row randomly. Find the probability that (i) the six girls sit together, (ii) the boys and girls sit alternately.

6 boys and 6 grils sit in a row at random. The probability that all the girls sit together is

Three boys and two girls stand in a queue. The probability, that the number of boys ahead is at least one more than the number of girls ahead of her, is

In an interview for a job, 5 boys and 3 girls appeared. If 4 persons are to be selected at randon from this group, then find the probability that 3 boys and 1 girl or 1 boy and 3 girls are selected.

In how many ways can 5 girls and 3 boys be seated in a row so that no two boys are together?

Cards marked with numbers 13, 14, 15.....60 are placed in a box and mixed thoroughly. One card is drawn at random from the box Find the probability that the sum of the digits of the number on the card is 5.

8 boys and 2 girls sit in a row randomly. The probability that two girls do not sit together is …………..

Find the number of ways in which 5 girls and 5 boys can be arranged a n row if boys and girls are alternative.

A box contains 90 discs which are numbered from 1 to 90. If one disc is selected at random from the box, find the probability that it bears (1) a two-digit number (ii) a perfect square number (iii) a number divisible by 5.

25% of the students in a school are girls and others are boys. Form an equation and draw a graph for this. By observing the graph, answer the following : (i) Find the number of boys, if the number of girls is 25. (ii) Find the number of girls, if the number of boys is 45. (iii) Take three different values for number of boys and find the number of girls. Similarly take three different values for number of girls and find the number of boys?