 Hello and welcome to the session. In this session we discussed the following question which says, How many envelopes can be made out of a sheet of paper, 220 cm by 100 cm? If each envelope requires a piece of paper of size, 11 cm by 20 cm. So we are given a sheet of paper measuring 220 cm by 100 cm and we are given that one envelope requires a piece of paper of size 11 cm by 20 cm. So we have to find out the number of envelopes made out of the given sheet of paper which measures 220 cm by 100 cm. Before finding the solution for this question, let's recall the formula to calculate the area of a rectangle. This is equal to L into B where this L is the length of the rectangle and B is the breadth of the rectangle. This is the key idea that we use in this question. Now let's see the solution for this question. First of all we will find out the area of the given sheet of paper. This would be equal to 220 cm multiplied by 100 cm. That is this is equal to 22000. That is 22000 cm square is the area of the given sheet of paper. The next we have the area of the piece of paper required for one envelope is equal to 11 cm multiplied by 20 cm. And so this is equal to 220 cm square. So area of the piece of paper required for one envelope is equal to 220 cm square and the area of the given sheet of paper is 22000 cm square. So the required number of envelopes is equal to the area of the given sheet of paper which is 22000 upon the area of the piece of paper required for one envelope that is 220 cm square. So 22000 over 220 is the required number of envelopes. Now the 0 cancels with the 0 and 2200 times 2200 so this is equal to 100. Thus we have the required number of envelopes is equal to 100. 100 is our final answer. This completes the session. Hope you have understood the solution of this question.