A circular field has a circumference 360 km . Three cyclist start together and can cycle 48,60 & 72 km a day,round the field .when will they meet again ??
Answers
First, we will get how much time all three cyclists take to cover a circumference of 360 km
So, the time taken for cyclist1 = 360/48 = 7.5 days
So, the time taken for cyclist2 = 360/60 = 6 days
So, the time taken for cyclist3 = 360/72 = 5 days
Here, LCM of 7.5, 6, 5 = 30
So, they will meet after 30 days.
Now, in 30 days, first cyclist will travel = 30/7.5 = 4 rounds
In 30 days, second cyclist will travel = 30/6 = 5 rounds
In 30 days, third cyclist will travel = 30/5 = 6 rounds
So, after 30 days, all the 3 cyclists will meet at starting point.
I hope this will help u
Speed of first, second and third cyclist are 48 km/day, 60 km/day and 72 km/day. In terms of km/hr,
48 km/day = 48/24 km/h = 2 km/h
60 km/day = 60 km/24 h
72 km/day = 72/24 km/h = 3 km/h
Time = Distance/Speed
Time for 1st cyclist = 360/2 = 180 hrs
Time for 2nd cyclist = 360/(60/24) = 144 hrs
Time for 3rd cyclist = 360/3 = 120 hrs
L.C.M of 180, 144, 120 = 720 hrs
Total Time taken in days = 720/24 = 30 days