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: in a 500 m race , the ratio of the speeds of two contestants a and b is 3 : 4 . a has a start of 155 m . then , a wins by : 
Options: a ) 60 m , b ) 20 m , c ) 40 m , d ) 20 m , e ) 23 m
c

Problem: a cistern of capacity 8000 litres measures externally 3.3 m by 2.6 m by 1.2 m and its walls are 5 cm thick . the thickness of the bottom is : 
Options: a ) 90 cm , b ) 2 dm , c ) 1 m , d ) 1.1 cm , e ) none of these
b

Problem: an electric pump can fill a tank in 3 hours . because of a leak in the tank , it took 12 hours to fill the tank . if the tank is full , how much time will the leak take to empty it ? 
Options: a ) 4 hours , b ) 12 hours , c ) 8 hours , d ) 5 hours , e ) 15 hours

a