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.
She has everything correct but one thing. In order to have her answer correct, she must put the 9 in front of the 7 because the bigger number needs to go in front.
