A, B and C start swimming in a pool simultaneously from the same end. To complete 12 laps, A takes 10 minutes, B takes 8 minutes and C takes 6 minutes. What is the ratio of speeds A:B:C?  Options: A) 3:4:5 B) 10:15:20 C) 5:4:3 D) 4:6:5 E) 12:15:25
The slowest one is A, then comes B and the fastest one is C. So, the the ratio of speeds A:B:C must be in ascending order. Eliminate options C, D, and E.   A's speed (distance)/(time) = 12/10 = 6/5 lap per minute = 10 laps in 10 minute;   B's speed (distance)/(time) = 12/8 = 3/2 lap per minute = 15 laps in 10 minutes;   C's speed (distance)/(time) = 12/6= 
<gadget id="calculator">12/6</gadget>
<output>2</output>
2 lap per minute= 20 laps in 10 minutes/   Therefore, the the ratio of speeds A:B:C is 12:15:20.   Answer: 10:15:20.
<result>B</result>
A, B and C start swimming in a pool simultaneously from the same end. To complete 12 laps, A takes 10 minutes, B takes 8 minutes and C takes 6 minutes. What is the ratio of speeds A:B:C?