the magnetic field is perpendicular to the the velocity so it will move in a circle....u can find the radius by equating
mv2/r = qvB
r = mv/qB
now the frictional force is μmg and is opposing the motion so the particle will decelerate,
hence, 1/2mv22 - 1/2mv2 = -μmgx2πr [work energy theorem]
1/2mv22 = 1/2mv2 - μmg2πr
therefore........μmg2πr < 1/2mv2....now put the values....
so according to my calculations, the answer will be anything less than 1/2Ï€