A particle moves for 10 seconds. It first accelerates form rest and then retards to rest. If the retardation is 4 times the acceleration, then time for which it accelerates will be
(1) 2 s
(2) 5 s
(3) 8 s
(4) 6 s
(1) 2 s
(2) 5 s
(3) 8 s
(4) 6 s