Q36. 
Dexter and Prexter are competing with each other in a friendly community competition in a pool of 50 m length and the race is for 1000 m. Dexter crosses 50 m in 2 min and Prexter in 3 min 15 sec. Each time they meet/cross each other, they do handshake's. How many such handshake's will happen if they start from the same end at the same time? 
A.  18 

B.  19 

C.  20 

D.  17 
Q37. 
A ball is thrown twice from a place with the gap of 34 minutes between the two shots. A person approaching this point in a bus heard the second shot 33 minutes after he heard the first shot. What is the speed of bus (in kmph) if sound travels at 330 m/s? 
A.  30 

B.  33 

C.  36 

D.  42 
Q38. 
A man and a woman 81 miles apart from each other, start travelling towards each other at the same time. If the man covers 5 miles per hour to the women's 4 miles per hour, how far will the woman have travelled when they meet? 
A.  27 

B.  36 

C.  45 

D.  None of these 
Q39. 
Three friends $A$, $B$ and $C$ run around a circular track of length 120 metres at speeds of 5 m/s, 7 m/sec and 15 m/sec, starting simultaneously from the same point and in the same direction. How often will the three of them meet? 
A.  Every 60 seconds 

B.  Every 120 seconds 

C.  Every 30 seconds 

D.  None of these 
Q40. 
A man can row 50 km upstream and 72 km downstream in 9 hours. He can also row 70 km upstream and 90 km downstream in 12 hours. Find the rate of current. 
A.  3 km/hr 

B.  8 km/hr 

C.  4 km/hr 

D.  None of these 