A new model of laptop is gradually replacing an earlier model. The projected sales (in thousands) for the old and new model are given by Sold=t+416andSnew=21t36. Find the time t for which the two models yield the same sales and determine the value of the sales. a. t=48/13 and S=R2080 b. t=1 and S=4000 c. t=28/13 and S=R4278 d. t=43/18 and S=R2000.