Six pictures are to be arranged from left to right on a wall of an art gallery for display. How many arrangements are possible ?

It is required to seat 5 men and 4 women in a row so that the women occupy the even places. How many such arrangements are possible ?

A teacher wants to arrange 5 students on the platform such that the boy ‘YUSUF’ occupies the first position and the girls ‘GEETA’ and ‘SEETA’ are always together. How many such arrangements are possible ?

When a group photograph in taken, all the seven teachers should be in the first row and all the twenty students should be in second row, If the two corners of the second row are reserved for the two tallest students, interchangeable only between them and if the middle seat of the front row is reserved for the principal, how many arrangements are possible?

The letters of the word ‘TUESDAY’ are arranged in a line, each arrangement ending with letter S. How many different arrangements are possible ? How many of them start with letter D ?

How metallic character vary on moving from left to right along a period?

Three boys and three girls are to be seated around a table in a circle. Among them, the boy X does not want any girl neighbour and the girl Y does not want any boy neighbour. How many such arrangements are possible ?

How does atomic size of elements vary on moving from left to right in a period

In cubic system how many atoms arrangement exsit in nature ?

Serial numbers for an item produced in a factory are to be made using two letters followed by four digits (0 to 9). If the letters are to be taken from the first six letters of English alphabet without repetition and the digits are also not repeated in a serial number, how many serial numbers are possible ?

How many lobes are present in right and left lung.