 Hello and welcome to the session, I am Deepika here. Let's discuss a question. Write the first four terms of the AP when the first term A and the common difference D are given as follows. A is equal to 10 and D is equal to 10. Now we know that an orthopedic progression is a list of numbers in which each term is obtained by adding a fixed number to the preceding term except the first term and the fixed number is called the common difference of the AP and it can be positive, negative or zero. So if the first term is then plus D, A plus 2D, 3D and so on, I take progression. The key idea behind that question is the help of this key idea to solve the upper questions. So let's start the question. Now it is given A is equal to 10 and B is also equal to 10. Now according to the key idea we have A, A plus D, A plus 2D, A plus 3D is an orthopedic progression. Therefore A which is 10, A plus D, 10 plus 10, A plus 2D, 10 plus 2 into 10, 10 plus 3 into 10 is an orthopedic progression. In the question we have to find the first four terms of an AP. Therefore 10, 40 are the first four terms. The answer for the above question is 10, 20, 30, 40 are the first four terms of an AP. I hope the solution is great to you. Bye and take care.