In a hall, 625 chairs are arranged in rows and columns,
with the number of rows equal to the number of
columns. The chairs in one row and one column are
removed. How many chairs remain?

Given that a matrix A contains 15 elements. Can A be a matrix with the number of rows=the number of columns ? Explain.

How many grams of carbon and oxygen are required to get the same number of atoms as in one gram of Helium?

Find the number of arrangements of 6 boys and 5 girls in a row so that no two girls sit together.

the number of children in one room is 20 and another room is 40 ? 5 biscuits are to be given to each. How many biscuits are needed?

There are 20 persons, among whom two are brothers. Find the number of arrangements of these persons in a row.

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?

Find the number of arrangements of 6 boys and 5 girls in a row so that boys and girls occupy alternate positons

. How many numbers are there in the 30^(th) row of this number pyramid?

The letters of the word "SOCIETY" are placed at random in a row Find the number of arrangements of the letters of the given word in a row so that the three vowels come together.

There are 50 children ina class.Thirty of them are girls . There are 40 children in another class. 25 of them are boys.One student is taken from each class at random. What is the number of outcomes ? How many out comes contain both boys. How many outcomes contain both girls. How many out comes have one boy and one girl.