Detailed Instructions: 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'.
Q: Problem: an employer pays rs . 20 for each day a worker works and for felts rs . 3 for each day is ideal at the end of sixty days a worker gets rs . 280 . for how many days did the worker remain ideal ?
Options: a ) 10 , b ) 40 , c ) 30 , d ) 20 , e ) 50
A:
b