Here , Mass of packet = 500 g

And Volume of packet `=350 cm,^(3)`

So , Density of packet`=("Mass of pakcet")/("Volume of packet")`

`=(500 g )/(350 cm^(3)`

since the density of packet `(1.42 g cm^(-3))` is more than the density of water `(1g cm ^(-3))`, therfore , the packet will sink in water .

The packet which sinks in water will displace water equal to its own volume .Since the volume of packet is `350 cm ^(3)` of water. We have now to calculate the mass of `350 cm^(2)` of water .

Now , `"Density of water =("Mass of water ")/(Volume of water ")` ltbr gt So, `1g cm^(-3)=("Mass of water ")/(350 cm ^(3))`

And Mass of water `=1 g cm^(-3)xx350 cm^(3))`

=350 g

Thus , the mass of water displaced by the packet is 350 grams.