When equal volumes of two metals are mixed together the specific gravity of alloy is 4. When equal masses of the same two metals are mixed together the specific gravity of the alloy becomes 3. find specific gravity of each metal?
(specific gravity `=("density of substance")/("density of water"))`

Explanation

In case of mixture, `rho_("mix")=(m_(1)+m_(2))/(V_(1)+V_(2))`
When equal volumes are mixed,
`=(rho_(1)+rho_(2))/(2)" …………(i)"`
When equal masses are mixed,
`=(2rho_(1)rho_(2))/(rho_(1)+rho_(2))" …………(ii)"`
Therefore, from (i) and (ii)
specific gravity of the metals are 2 and 6.