Question

Three bus services A, B and C

arrive at a station. Service A

arrives at the station every 15

minutes, service B arrives every

20 minutes and service C arrives

every 30 minutes. All three buses

arrive at the station together at 9

a.m. At what time will the three

buses next arrive at the station 100 points for correct answers ​

Answer 1

$\huge{\mathcal{\purple{A}\pink{N}\purple{S}\pink{W}\purple{E}\pink{R}\purple{:}\pink{:}}}$

Calculate their LCM and add it to 9:00 AM

$\sf{=\: 60\: min\: =\: 1hour}$

$\sf{=\: 9:00\: AM\: +\: 1hour}$

$\sf{=\: 10:00\: AM}$

The three buses will arrive next (at the same time) at 10:00 AM

Answer 2

Find the least common multiple of 15,20,30.

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15 = 3×5

20 = 2×2×5

30 = 2×3×5

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lcm = 2×2×3×5 = 60

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60 min = 1 hrs.

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Ans: 10:00 am