TASK DEFINITION: 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: Problem: a and b together can do a piece of work in 10 days . b alone can finish it in 20 days . in how many days can a alone finish the work ? 
Options: a ) 20 , b ) 10 , c ) 15 , d ) 5 , e ) 7

SOLUTION: a

PROBLEM: Problem: a train , 800 meter long is running with a speed of 78 km / hr . it crosses a tunnel in 1 minute . what is the length of the tunnel ? 
Options: a ) 650 meter , b ) 555 meter , c ) 500 meter , d ) 458 meter , e ) none of these

SOLUTION: c

PROBLEM: Problem: city a to city b , john drove for 1 hour at 40 mph and for 3 hours at 60 mph . what was the average speed for the whole trip ? 
Options: a ) 57 , b ) 57.5 , c ) 58.2 , d ) 59 , e ) 55

SOLUTION:
e