Task: Question Answering
Input (English): Problem: walking at 4 / 5 of her normal speed , a worker is 15 minutes later than usual in reaching her office . the usual time ( in minutes ) taken by her to cover the distance between her home and her office is 
Options: a ) 45 , b ) 50 , c ) 55 , d ) 60 , e ) 65
Output (English): d