(ii) From the graph, the required number of days to complete the work when the company decides to work with workers is days. Also, from = xy if = , then (iii) From the graph, if the work has to be completed by days, the number of workers required is . Also, from = xy if y = , then x = Example . Nishanth is the winner in a Marathon race of km distance.
He ran at the uniform speed of km/hr and reached the destination in hour. He was followed by Aradhana, Jeyanth, Sathya and Swetha with their respective speed of km/hr, km/hr, km/hr and km/hr. And, they covered the distance in hrs, hrs, hrs and hours respectively. Draw the speed-time graph and use it to find the time taken to Kaushik with his speed of .
km/hr. Solution: Let us form the table with the given details. Speed x (km/hr) Time y (hours) From the table, we observe that as x decreases, y increases. Hence, the type is inverse variation.
Let = k ⇒ > xy k k is called the constant of variation. From the table k = × = × = … = × = Therefore, xy = . Plot the points ( , ), ( , ), ( , ), ( , ), ( , ) and join these points by a smooth curve (Rectangular Hyperbola). From the graph, we observe that Kaushik takes hrs with a speed of .