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: pipe a fills a tank of capacity 850 liters at the rate of 40 liters a minute . another pipe b fills the same tank at the rate of 30 liters a minute . a pipe at the bottom of the tank drains the tank at the rate of 20 liters a minute . if pipe a is kept open for a minute and then closed and pipe b is open for a minute and then closed and then pipe c is open for a minute and then closed and the cycle is repeated , when will the tank be full ?
Options: a ) 42 minutes , b ) 51 minutes , c ) 39 minutes , d ) 40 minutes 20 seconds , e ) none of these
[EX A]: b

[EX Q]: Problem: how many shots of 1 cm radius can be prepared from a sphere of 4 cm radius ?
Options: a ) 33 , b ) 88 , c ) 27 , d ) 64 , e ) 99
[EX A]: d

[EX Q]: Problem: the cross - section of a cannel is a trapezium in shape . if the cannel is 5 m wide at the top and 3 m wide at the bottom and the area of cross - section is 3800 sq m , the depth of cannel is ?
Options: a ) 920 , b ) 930 , c ) 940 , d ) 950 , e ) 960
[EX A]:
d