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'.

Problem: a can do a piece of work in 8 days and b alone can do it in 12 days . how much time will both take to finish the work ?
Options: a ) a ) 4.8 , b ) b ) 6.333 , c ) c ) 7.333 , d ) d ) 8.5 , e ) e ) 9
a

Problem: a and b runs around a circular track . a beats b by one round or 10 minutes . in this race , they had completed 4 rounds . if the race was only of one round , find the a ' s time over the course :
Options: ['a ) 8.5 min', 'b ) 7.5 min', 'c ) 1.5 min', 'd ) 9.5 min', 'e ) 4.5 min']
b

Problem: from mumbai railway station , two trains a and b start simultaneously from stations 400 miles apart , and travel the same route toward each other on adjacent parallel tracks . if train a and train b travel at a constant rate of 40 miles per hour and 40 miles per hour , respectively , how many miles will train a have traveled when the trains pass each other , to the nearest mile ?
Options: a ) 112 , b ) 133 , c ) 150 , d ) 167 , e ) 180
e