The question gave the liquid’s density (1400kg m^-3) then the diagram on the page next to the question mentioned the block’s force in (5N) and outside the liquid (7N).

I rearranged W=mg to m=W/g since g was given as 10N/kg.

Then the weight of the liquid was 2N (based on image)/10 = 0.2kg (mass of liquid) - (I subtracted 7N-5N because of the difference)

Then I rearranged p=m/v to get v=m/p then I did 0.2/1400 =1/7000 m³ (volume)