Q21. 
A ship 77 km from the shore, springs a leak which admits to 9/4 tonnes of water in 11/2 minutes. 92 tonnes of water would sink it. But the pumps can throw out 12 tonnes of water per hour. Find the average rate of sailing so that the ship may just reach the shore as it begins to sink. 
A.  10.5 km/hr 

B.  11 km/hr 

C.  10 km/hr 

D.  12.5 km/hr 
Q22. 
A train covered a certain distance at a uniform speed. If the train had been 6 km/hr faster, it would have taken 4 hour less than the scheduled time. And, if the train were slower by 6 km/hr, the train would have taken 6 hr more than the scheduled time. The length of the journey is: 
A.  700 km 

B.  740 km 

C.  720 km 

D.  760 km 
Q23. 
Two identical trains $A$ and $B$ running in opposite direction at same speed tale 2 min to cross each other completely. The number of bogies of $A$ are increased from 12 to 16. How much more time would they now require to cross each other? 
A.  40 sec 

B.  50 sec 

C.  60 sec 

D.  20 sec 
Q24. 
A boatman rows to a place 45 km distant and back in 20 hour. He finds that he can row 12 km with the stream in the same time as 4 km against the stream. Find the speed of the stream. 
A.  3 km/hr 

B.  2.5 km/hr 

C.  4 km/hr 

D.  3.5 km/hr 
Q25. 
A motorboat whose speed is 15 km/hr in still water goes 30km downstream and comes back in four and a half hours. The speed of the stream is: 
A.  4.5 km/hr 

B.  6 km/hr 

C.  7 km/hr 

D.  5 km/hr 