0.775gcm-3
0.875gcm-3
0.780gcm-3
0.880gcm-3
Correct answer is A
\(V_A = \frac{M}{D} = \frac{21}{0.7} = 30cm^3\)
\(V_w = \frac{M}{D} = \frac{10}{1} = 10cm^3\)
Vmixture = 30 + 10 = 40cm3
Mmixture = 21 + 10 = 31g
Dmixture = \(\frac{m}{v} = \frac{31}{40} = 0.775\)