# Moderate Time, Speed & Distance Solved QuestionAptitude Discussion

 Q. 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

Solution:
Option(B) is correct

When Dexter completes the second round, they do handshake once.

Now for every round which Dexter completes, there will be one handshake 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:
$20−1 =\textbf{19}$

Edit: For an alternative solution, check comment by Prasanna Jd.

## (1) Comment(s)

Prasanna Jd
()

Considering both of them start at the same time they have to do 20 times $(=\frac{1000}{50})$ to complete the race, now take Dexter as he is fast, in the first round they don't clap eachothre implies we are left with
$20-1=19$ chances