Question

To mix plaster for a dental model, 35 mL of water is used for 100g of plaster. How many mL of water should be used for 250g of plaster? Round your final answer to 1 decimal place if necessary.

Answer 1

Okay, here we have this:

Considering the provided information, we are going to calculate the requested value, so we obtain the following rule of three:

$\begin{gathered} \frac{x}{35mL\text{ of water}}=\frac{250g\text{ of plaster}}{100g\text{ of plaster}} \\ x=\frac{250g\text{ of plaster}}{100g\text{ of plaster}}\cdot35mL\text{ of water} \end{gathered}$

Solving for x:

$\begin{gathered} x=2.5\cdot35mL\text{ of water} \\ x=87.5mL\text{ of water} \end{gathered}$

Finally we obtain that 87.5mL of water should be used for 250g of plaster.