Did I do this correctly or do I need to try again?

What is the mass percent of a solution when 18.6 g of table salt is added to 81.4 g of water?

Mass Percent = mass of solute(g)x100

mass of solution (g)
= 18.6 g x100
18.6 g + 81.4g

= 18.6 g x 100
100g

= 0.186 x 100
= 18.6
The mass percent of the solution is 18.6%

You number is correct; if you obtained it correctly from your work I can't tell.

mass percent = (mass solute/100 g solution)*100

[(18.6)/(18.6 + 81.4)]*100 =
(18.6/100)*100 = 18.6%

To determine if you calculated the mass percent correctly, you can follow the formula correctly. The formula for calculating mass percent is:

Mass Percent = (mass of solute / mass of solution) x 100

In this case, the mass of the solute is 18.6 g (table salt) and the mass of the solution is 18.6 g (table salt) + 81.4 g (water) = 100 g.

Plugging in these values into the formula:

Mass Percent = (18.6 g / 100 g) x 100

Simplifying the equation:

Mass Percent = 18.6%

So, yes, your calculation is correct. The mass percent of the solution is indeed 18.6%.