Ana climbs up stairs 20 floors building and back. She takes the exact same route both ways. On the trip up she climbs an average speed of 2 steps per second. On the trip back she climbs down at an average speed of 4 steps per second. What is her approximate average speed for the round trip in miles per hour? Choose the correct choice from the following answers: A) 1 B) 1.25 C) 1.33 D) 1.5 E) 1.75
Average speed = total distance/total time   Here number of steps to 20th floor and back is same as she takes the same route.   D = 2T1 and D=4T2   Therefore, T1 = D/2 and T2 = D/4   T1+T2 = 3D/4   Therefore, average speed  1+ 2= 
<gadget id="calculator"> 1+ 2</gadget>
<output>3</output>
3D/4   Therefore, average speed= 2d/3d/4 =2d * 4/3d   Answer is 1.3 Since, the options are far away we need not solve till the decimal points   So correct answer is option 1.33
<result>C</result>
Ana climbs up stairs 20 floors building and back. She takes the exact same route both ways. On the trip up she climbs an average speed of 2 steps per second. On the trip back she climbs down at an average speed of 4 steps per second. What is her approximate average speed for the round trip in miles per hour?