In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
Example: Problem: walking at 5 / 6 th of its usual speed a cab is 15 mnts late . find its usual time to cover the journey ? 
Options: a ) 25 m , b ) 45 m , c ) 32 m , d ) 75 m , e ) 62 m
Example solution: d
Example explanation: New speed = 5 / 6 th of usual speed new time = 6 / 5 th of usual time 6 / 5 ut - ut = 15 m ut / 5 = 15 m ut = 75 m answer is d

Problem: Problem: a is 30 % more efficient than b . how much time will they working together take to complete a job which a alone could have done in 23 days ? 
Options: a ) 11 , b ) 13 , c ) 20 3 / 17 , d ) 14 , e ) none of these

Solution: b