 follow and welcome to the session. Today I will help you with the following question. The question says, formulate the following problem as a pair of equations and hence find its solution. Ritu can draw downstream 20 kilometers in 2 hours and upstream 4 kilometers in 2 hours. Find her speed of rowing in still water and the speed of the current. Let's move on to the solution. We are supposed to find the speed of rowing in still water and the speed of the current. So, let the speed of rowing till water be u kilometers per hour and let the speed of the current be v kilometers per hour. Now let's find out the speed downstream. We already know that speed is equal to distance upon time and we know from the question that the distance covered downstream is 20 kilometers and the time is 2 hours so we have speed downstream would be equal to 20 upon 2 that is equal to 10 kilometers per hour. We also know that speed downstream is equal to speed of rowing in still water plus the speed of current and we have taken speed of rowing in still water as u kilometers per hour and speed of current as v kilometers per hour so we have speed downstream is equal to u plus v kilometers per hour. But we already found out that speed downstream is 10 kilometers per hour so we get the equation u plus v is equal to 10. Let's name this equation as 1. Now let's find out the speed upstream. We know that speed is equal to distance upon time so from the question we have that the distance covered upstream is 4 kilometers and the time is 2 hours so we get speed upstream is equal to distance 4 upon time 2 and this is equal to 2 kilometers per hour. We know that speed upstream is equal to speed of rowing in still water minus speed of current so this becomes equal to u minus v that is we get speed upstream is equal to u minus v kilometers per hour but we have found out that speed upstream is 2 kilometers per hour so we get u minus v is equal to 2. Let's name this equation as 2. Thus the equations u plus v equal to 10 and u minus v equal to 2 represents the given problem. We are supposed to find the solution of both these equations for this we will add these two equations this v and this v gets cancelled and we have 2 u is equal to 10 plus 2 that is 12. Now dividing both the sides by 2 gives us u is equal to 6. We shall substitute u equal to 6 in this equation that is u plus v equal to 10 then on substituting u equal to 6 in this equation we get plus v equal to 10. Now to find the value for v we will transpose this term 6 to the right hand side so we get v is equal to 10 minus 6 that is v is equal to 4. Thus the solution for the given pair of equations is u equal to 6 and v equal to 4. Hence the final answer is u plus v equal to 10 u minus v equal to 2 where u and v are respectively speeds in kilometer per hour of rowing and current also the solution is u equal to 6 and v equal to 4. Hope you enjoyed the session have a good day.