Penetration and deceleration to rest

A bullet or body decelerates uniformly while penetrating a medium (wooden block, plank), and the question asks for additional penetration distance or number of planks needed to stop it.

jee-main 2002 Q4 View
If a body looses half of its velocity on penetrating 3 cm in a wooden block, then how much will it penetrate more before coming to rest?
(1) 1 cm
(2) 2 cm
(3) 3 cm
(4) 4 cm