Desmos Graphing Calculator

CalcReferenceCopy

Math·Algebra·Linear equations in one variable

medium

A biologist mixed a solution that is $0.3\%$ sodium chloride by mass with a solution that is $0.15\%$ sodium chloride by mass to obtain a new solution, which has a mass of $80$ grams and contains $0.21$ grams of sodium chloride. How many grams of $0.3\%$ sodium chloride solution did the biologist use?

A

$0.14$

B

$20$

C

$60$

D

$79.86$