1. The problem statement, all variables and given/known data I've worked through and been able to understand each problem I've been given except for the following two, does anyone have a suggestion or an explanation on how to solve either of these problems? Thanks in advance. 1. "On the first part of a 317 mile trip, a sales representative averaged 58 miles per hour. The sales representative averaged only 52 miles per hour on the last part of the trip because of an increased volume of traffic. Find the amount of driving time at each speed if the total time was 5 hours and 45 minutes." 2. "The cooling system on a truck contains 5 gallons of coolant that is 40% antifreeze. How much must be withdrawn and replaced with 100% antifreeze to bring the coolant in the system to 50% antifreeze?" 2. Relevant equations s=d/t 3. The attempt at a solution I don't even know where to begin with these two. Regarding #1 something to the effect of '58m/h +52m/h = 317m/5.75h. But I'm not sure to go from there.