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: raja complete a journey in 10 hours . he travels first half of the journey at the rate of 21 km / hr and second half at the rate of 24 km / hr . find the total journey in km . 
Options: a ) 200 km , b ) 250 km , c ) 224 km , d ) 255 km , e ) 260 km
c

Problem: a train 120 m long running at 60 kmph crosses a platform in 20 sec . what is the length of the platform ? 
Options: a ) 213 , b ) 298 , c ) 350 , d ) 726 , e ) 267
a

Problem: if 20 men can build a water fountain 56 metres long in 42 days , what length of a similar water fountain can be built by 35 men in 3 days ? 
Options: a ) 3 m , b ) 4 m , c ) 7 m , d ) 9 m , e ) 10 m

c