The numbers 2 3 4 5 6 7 8 are to be placed one per square in the diagram as shown below such that the sum of the four numbers in the horizontal row as well as vertical row is 21 then the number of ways in which this can be done is ?

Six X have to be placed in the squares of figure such that each row contains at least one X. The number of ways in which this can be done is:

Complete the magic square given below, so that the sum of the number in each row or in each column or along each diagonal is 15

5 men and 6 women have to be seated in a straight row so that no two women are together. Find the number of ways this can be done.

The number of ways in which 5X 's can be placed in the squares of the figure so that no row remains empty is:

It is possible to arrange eight of the nine numbers 2, 3, 4, 5, 7, 10, 11, 12, 13 in the vacant squares of the 3 by 4 array shown below so that the arithmetic average of the numbers in each row and column is the same integer. Which one of the nine numbers must be left out when completing the array ?

Six X 's have to be placed in the squares of the figure below, such that each row contains atleast one X. in how many different ways can this be done?

It is possible to arrange eight of the nine numbers 2, 3, 4, 5, 7, 10, 11, 12, 13 in the vacant squares of the 3 by 4 array shown below so that the arithmetic average of the numbers in each row and column is the same integer. The arithmetic average is

Each of 8 identical balls is to be placed in the squares shown in the figure given in a horizontal direction such that one horizontal row contains 6 balls and the other horizontal row contains 2 balls. In how many maximum different ways can this be done