A and B start swimming simultaneously from two points P and Q
respectively, on a river towards each other. A crosses a floating cork
at a point S and B crosses the floating cork at a point T which is at a
distance of 8 km from point S. A and B cross each other at a distance of
2 km from T. It is given that the direction of flow of the river is
from P to Q and in still water, the ratio of speeds of A and B is 3 : 1.
P, S, T and Q ( in that order) are on the same straight line and assume
that A, B and the floating cork move along that line.If PQ = 100 km, then find the distance between the floating cork and A when A reaches Q

1) 11
2) 12
3) 13
4) 14
5) NOT