Answer:
40.5 g
Step-by-step explanation:
Find how much salt is in 450 g of a 9% salt solution.
Note that
450 g - 100%,
x g - 9%,
then
[tex]\dfrac{450}{x}=\dfrac{100}{9},\\ \\x=\dfrac{450\cdot 9}{100}=40.5\ g.[/tex]
If you evaporated all water from this solution, then you would get 40.5 g of salt.