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'.
--------
Question: Problem: a can do a piece of work in 10 days . he works at it for 4 days and then b finishes it in 9 days . in how many days can a and b together finish the work ? 
Options: a ) 6 , b ) 7 , c ) 5 , d ) 4 , e ) 1

Answer: a


Question: Problem: the speed of a boat in still water is 15 km / hr and the rate of current is 3 km / hr . the distance travelled downstream in 12 minutes is 
Options: a ) 1.2 km , b ) 1.8 km , c ) 2.4 km , d ) 3.6 km , e ) 1.6 km

Answer: d


Question: Problem: one computer can upload 100 megabytes worth of data in 3 seconds . two computers , including this one , working together , can upload 1300 megabytes worth of data in 30 seconds . how long would it take for the second computer , working on its own , to upload 100 megabytes of data ? 
Options: a ) 6 , b ) 10 , c ) 9 , d ) 11 , e ) 13

Answer:
b