the distance from city a to city b is 100 miles. while driving from city a to city b, bob drives at a constant speed of 40 miles per hour. alice leaves city a 30 minutes after bob. what is the minimum constant speed in miles per hour that alice must exceed in order to arrive in city b before bob?
Choose the most appropriate option.
A) 45  B) 48  C) 50  D) 52  E) 54
<gadget id="calculator">100 / 40</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">30 / 60</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(5/2) - (1/2)</gadget>
<output>2</output>

<gadget id="calculator">100 / 2</gadget>
<output>50</output>

<result>C</result>
the distance from city a to city b is 100 miles. while driving from city a to city b, bob drives at a constant speed of 40 miles per hour. alice leaves city a 30 minutes after bob. what is the minimum constant speed in miles per hour that alice must exceed in order to arrive in city b before bob?
divide(100, subtract(divide(100, 40), divide(30, const_60)))
"the time it takes bob to drive to city b is 100 / 40 = 2.5 hours . alice needs to take less than 2 hours for the trip . alice needs to exceed a constant speed of 100 / 2 = 50 miles per hour . the answer is c ."