Answer:
specific gravity = 0.8 
specific gravity of solution = 2
Step-by-step explanation:
given data 
rectangular block above water = 0.400 in
rectangular block below water = 1.60 in
material floats below water = 0.800 in
solution
first we get here specific gravity of block that is 
specific gravity = block vol below ÷ total block vol × specific gravity water ..............1
put here value we get 
specific gravity = 
 × 1
 × 1
specific gravity = 0.8 
and now we get here specific gravity of solution that is express as
specific gravity of solution = total block vol ÷ block vol below × specific gravity block ........................2
put here value we get 
specific gravity of solution = 
 × 0.8
 × 0.8
specific gravity of solution = 2