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 sector of a circle has radius of 21 cm and central angle 180 o . find its perimeter ? 
Options: a ) 91.5 , b ) 92 , c ) 108 , d ) 94 , e ) 95
c

Problem: a can do a piece of work in 18 days and b alone can do it in 10 days . b works at it for 5 days and then leaves . a alone can finish the remaining work in 
Options: a ) 5 days , b ) 6 days , c ) 7.5 days , d ) 8.5 days , e ) 9 days
e

Problem: a fort had provision of food for 150 men for 45 days . after 15 days , 25 men left the fort . the number of days for which the remaining food will last , is : 
Options: a ) 36 , b ) 37 1 / 4 , c ) 42 , d ) 54 , e ) 48

a