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 can finish a work in 18 days and b can do same work in half the time taken by a . then working together , what part of same work they can finish in a day 
Options: a ) 1 \ 5 , b ) 1 \ 6 , c ) 1 \ 7 , d ) 1 \ 8 , e ) 1 \ 9
b

Problem: the edges of three metal cubes are 1 cm , 2 cm , and 4 cm respectively . a new cube is made by melting these three cubes together . what is the edge of the new cube ( in centimeters ) ? 
Options: a ) 3.8 , b ) 4.2 , c ) 4.6 , d ) 5.0 , e ) 5.4

b