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?	Select the correct option
A) 17  B) 18  C) 19  D) 20  E) 22

Rationale: explanation : when dexter completes second round , they do handshake once . now for every round which dexter completes , there will be one hand shake as the ratio of speed is 13 : 8 . d and p will meet at the pool end only after d completes 26 rounds . in the 20 th round , d finish the race and the total handshake ' s will be : 20 − 1 = 19 . answer : c
Answer: C