advita wrote:## A, B and C run around a circular track of length 750m at speeds of 3 m/sec, 6 m/sec and 18 m/sec respectively. If all three start from the same point, simultaneously and run in the same direction, when will they meet for the first time after they start the race?
A. 750 seconds
B. 50 seconds
C. 250 seconds
D. 375 seconds
E. 75 seconds
Oa-...C
pl show your proceedings/steps. thanks.
We can plug in the answer choices, which represent the first time the 3 runners will meet.
In order for A, B and C to meet, the two fastest runners -- B and C -- must go around the track at least once in order to catch up to A.
Since the rate for B = 6 m/sec, and the distance = 750m, we know that at least 750/6 = 125 seconds must elapse before the 3 runners will meet. Eliminate B and E.
Answer choice C: 250 seconds
Distance for A = r*t = 3*250 = 750. 750 = 1 time around the track.
Distance for B = r*t = 6*250 = 1500. 1500/750 = 2 times around the track.
Distance for C = r*t = 18*250 = 4500. 4500/750 = 6 times around the track.
Thus, after 250 seconds, all 3 runners will be meet at the starting point.
The correct answer is
C.
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