 We are going to learn about unitary method and this method involves finding worth of a single unit when we want to find out the worth of multiple units. Examples of such kind involve problems like this. Cost of 9 shirts is 3600 rupees then find out the cost of 5 shirts. Now this problem can be solved using different methods and one of them is a unitary method. So in order to find the answer using unitary method remember that we need to find the worth of single unit. Here unit is a shirt and what we mean here is finding the worth of a single shirt and here worth is basically the cost. So we have 9 shirts costing 3600 rupees so first find out the cost of one shirt and how do we do that? Take that unit in the denominator and we want to write 9 shirts and write the worth of it in the numerator so 3600 and so this gives us 400 rupees per shirt. So this means that one shirt costs 400 rupees. Now once we have found the worth of or the cost of one unit or one shirt in this case we can go ahead and find out the cost of 5 shirts now. We are multiplying 1 with 5 so we will have to multiply 400 with 5 as well and so the cost of 5 shirts will be 400 times 5 which is nothing but rupees 2000 and therefore the cost of 5 shirts is 2000 rupees. Let us solve one more problem. So in this problem we have that if Dhoni scored 21 runs in 3 overs how many runs will he score in 7 overs? Now again we need to find out what is the worth and what is the unit here right worth is runs and the unit is an over right we have to find the worth of a single unit. So we need to answer how many runs Dhoni scores in a single over. We take the unit in the denominator so unit is the over so there are 3 overs and then we put the worth for those many units which is basically the runs in the numerator so this gives us the worth of a single unit and in this case basically the runs for single over. Once we compute that we find that these are 7 runs for single over. So Dhoni is scoring 7 runs per over we need to find out how many runs will he score in 7 overs. So let us write 1 over 7 runs so 7 overs how many runs? So basically we are multiplying the runs scored in 1 over by 7 so we will also multiply this by 7 and we can say that Dhoni can score 7 times 7 runs in 7 overs. So in 7 overs Dhoni can score 49 runs and this is the answer that we have found. The important step in unitary method is that once you have found the worth for a single unit you will have to multiply the worth by the number of units that appear in the question. So first you divide like this and then you multiply in the last step to get the answer.