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'.

[EX Q]: Problem: two taps a and b can fill a cistern in 12 minutes and 18 minutes respectively . they are turned on at the same time . if the tap a is turned off after 4 minutes , how long will tap b take to fill the rest of the cistern ? 
Options: a ) 8 min . , b ) 9 min . , c ) 10 min . , d ) 7 min . , e ) none of these
[EX A]: a

[EX Q]: Problem: a tank can supply water to a village for 60 days . if a leak at the bottom of the tank drains out 10 liters per day , the supply lasts for 45 days only . for how many days will the supply last if the leak drains out 20 liters per day ? 
Options: a ) 15 , b ) 18 , c ) 20 , d ) 24 , e ) 36
[EX A]: e

[EX Q]: Problem: a goods train runs at the speed of 72 km / hr and crosses a 290 m long platform in 26 sec . what is the length of the goods train ? 
Options: a ) 278 , b ) 166 , c ) 151 , d ) 230 , e ) 109
[EX A]:
d