floating bodies

let the mass of the stones be m and the mass of the boat be M

initially ,

let the water displaced by the system =V

then pVg=(M+m)g

V=M/ρ + m/ρ

finally let the water displaced be V'

V'= water displaced by M(V1) water displaced by m(V2)

then

pV1g=Mg
V1=M/ρ

let density of stones=ρs

as ρs>p

the stones will be immersed

volume displaced= volume of stones = m/ps

hence V' = M/ρ + m/(ρs)

V'-V=m(1/ps-1/p)

as ps>p
V'<V

hence as water displaced is less
water level will decrease

rohan actually we discussed the same questions in the class a few days before.
what u have said is correct but it need not be the case always. check once again.. u are makng some assumptions while getting to the answer.

assumption = ps>p

guyzzz. this is a very standard ques............ d water level will decrease even if our logic says no.....physics does so........

and for the sake of being practical we can think of the level of the water being decreased with respect to the boat as the stones are unloaded !!