Question

With the help of a activity determine the equal volume of different substances having diffetent mass

Answer 1

it's just the density term I guess missing out badly...
change it it can be nutritino star or a helium balloon...
I hope you understand my point

Answer 2

take two identical glass fill both of them to equal level with water and kerosene
now measure their weight
u will find mass of water is more than mass of one glass of water so.. it happens due to different density more the density more will be the mass