Final answer:
A speed will appear as a lower number when expressed in miles per hour (MPH) compared to the same speed expressed in knots, because one knot is equivalent to approximately 1.15078 MPH.
Step-by-step explanation:
If a speed is expressed in miles per hour (MPH), and the same speed is expressed in knots, the number representing the speed will be different due to the units used. One knot is defined as 1 nautical mile per hour, and is equivalent to approximately 1.15078 MPH.
Therefore, the same speed will appear as a lower number when expressed in MPH compared to knots. This is because a mile is shorter than a nautical mile, so it takes more miles to cover the same distance in one hour. Therefore, the correct answer is (a) less.