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: the curved surface of a sphere is 64 π cm 2 . find its radius ? 
Options: ['a ) 8', 'b ) 3', 'c ) 4', 'd ) 9', 'e ) 7']
c

Problem: the ratio of efficiency of a is to c is 5 : 3 . the ratio of no . of days taken by b is to c is 2 : 3 . a takes 6 days less than c , when a and c completes the work individually . b and c left the work after 2 days . the no of days taken by a to finish the remaining work ? 
Options: a ) 4.5 , b ) 5 , c ) 6 , d ) 7 , e ) 8
c

Problem: two tains of equal lengths take 10 seconds and 16 seconds respectively to cross a telegraph post . if the length of each train be 120 metres , in what time ( in seconds ) will they cross each other travelling in opposite direction ? 
Options: a ) 12 , b ) 14 , c ) 16 , d ) 12.3 , e ) 18

d