You back packed for a distance of 15.75 miles today. you back packed at an average speed of 1.26 miles per hour, how long did you spend backpacking

Let us first concentrate and write down all the information's given in the question. Based on these information's the answer to the question can be easily deduced.
Distance for which back packing was done = 15.75 miles
Average speed of back packing = 1.26 miles/hour
Since
Speed = Distance/Time
Time = Distance/speed
Time spend for back packing = 15.75/1.26 hour
                                               = 12.5 hour
So the total time taken for back packing is 12.5 hours. I hope this is the answer you were looking for and the procedure is clear to you.

The answers are 20,30,80,180,960,890,1230,4560. on the first row