TASK DEFINITION: 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: Problem: if 21 lines are drawn in a plane such that no two of them are parallel and no three are concurrent , then in how many points do they intersect ? 
Options: a ) 150 , b ) 170 , c ) 190 , d ) 210 , e ) 230

SOLUTION: d

PROBLEM: Problem: a train running at the speed of 120 km / hr crosses a pole in 18 seconds . what is the length of the train ? 
Options: a ) 560 , b ) 570 , c ) 580 , d ) 590 , e ) 600

SOLUTION: e

PROBLEM: Problem: a and b together can complete a work in 12 days . a alone complete it in 20 days . if b does the work only for half a day daily , then in how many days a and b together will complete the work ? 
Options: a ) 110 days , b ) 11 days , c ) 15 days , d ) 20 days , e ) 17 days

SOLUTION:
c