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? Pick.
A) 1  B) 1.25  C) 1.33  D) 1.5  E) 1.75

Rationale: average speed = total distance / total time here number of steps to 20 th floor and back is same as she takes the same route . d = 2 t 1 and d = 4 t 2 therefore , t 1 = d / 2 and t 2 = d / 4 t 1 + t 2 = 3 d / 4 therefore , average speed = 2 d / 3 d / 4 = 2 d * 4 / 3 d answer is 1.3 since , the options are far away we need not solve till the decimal points so correct answer is option c
Answer: C