M_a->"Weight of alloy in air"=87gwtMa→Weight of alloy in air=87gwt
M_w->"Weight of alloy in watwr"=71gwtMw→Weight of alloy in watwr=71gwt
M_a-M_w->"Apparent loss in weight"Ma−Mw→Apparent loss in weight
=87-71=16gwt=87−71=16gwt
As per Archmedes principle the apoarent loss in weight here is equal to the weight of displaced water=16gwt=16gwt.
So mass of displaced water 16g16g
Taking density of water=1gcm^-3=1gcm−3 we can say that the volume of displaced water or the volume of the alloy-mass is
=(16g)/(1gcm^-3)=16cm^3=16g1gcm−3=16cm3
Hence density of the alloy is
d_"alloy"="Its mass"/"Its volume"=(87g)/(16cm^3)=5.437gcm^-3dalloy=Its massIts volume=87g16cm3=5.437gcm−3