Q. 5:Two ants A and B start from a point P on a circle at the same time, with A moving clock-wise and B moving anti-clockwise. They meet for the first time at 10:00 am when A has covered 60% of the track. If A returns to P at 10:12 am, then B returns to P at
1. 10:18 am
2. 10:25 am
3. 10:27 am
4. 10:45 am
Ratio of speed of A and B = ratio of distance covered by them = 60%/40% = 3/2
Let the speed of A = 3v , speed of B = 2v
Let the circumference = 10x
As They meet for the first time at 10:00 am when A has covered 60% of the track, so distance remain to cover for A and B will be 40% (4x) and 60% (that is 6x) respectively.
Given , 4x/3v = 12 min or x/v = 9 min
So 6x/2v = 3*(x/v) = 3*9 = 27 min
Thus B will return at P at 10:27 am.