Final answer:
A vest made of 15 layers of Kevlar without steel plates can stop all rounds except rifle rounds.
Step-by-step explanation:
A vest made of 15 layers of Kevlar without steel plates could stop all rounds except for Rifle rounds. Kevlar is a strong material that is used in bulletproof vests for its ability to absorb and distribute the impact of bullets. While it is highly effective against handgun rounds and shotgun pellets, it may not provide enough protection against the high velocity and penetrating power of rifle rounds.