14. nellie runs the length of a 100 - yard football field in a time of 20 seconds. her average running speed…

14. nellie runs the length of a 100 - yard football field in a time of 20 seconds. her average running speed is\na) 1/2 yard/second.\nb) 5 yards/second.\nc) 50 yards/second.\nd) not enough information
Answer
Explanation:
Step1: Recall speed formula
Speed = $\frac{Distance}{Time}$
Step2: Substitute values
Distance = 100 yards, Time = 20 seconds. So Speed = $\frac{100}{20}$
Step3: Calculate result
$\frac{100}{20}=5$ yards/second
Answer:
B. 5 yards/second