To find out how long it will take to load 6 1/2 trucks, we first need to determine how long it takes to load one truck. If 3 1/2 trucks take 42 minutes, we can calculate the time for one truck by dividing the total time by the number of trucks.
3 1/2 trucks is equivalent to 3.5 trucks. Therefore, we have:
Time for one truck = Total time / Number of trucks = 42 minutes / 3.5 trucks
Calculating that:
Time for one truck = 42 / 3.5 = 12 minutes.
Now that we know it takes 12 minutes to load one truck, we can find the time for 6 1/2 trucks. First, convert 6 1/2 trucks into a decimal form, which is 6.5 trucks.
Time for 6 1/2 trucks = Time for one truck * Number of trucks
Time for 6.5 trucks = 12 minutes * 6.5 = 78 minutes.
Thus, it will take a total of 78 minutes to load 6 1/2 trucks.