A chemist mixed $x$ liters of a $6\%$ saline solution with $y$ liters…

Question

Prompt

A chemist mixed

x

liters of a

6%

saline solution with

y

liters of a

9%

saline solution to produce a

7%

saline solution. Which equation best represents this situation? (Assume the volumes of the solutions are additive.)

0.06 x + 0.09 y = 7 (x + y)

0.06 x + 0.09 y = 0.07 (x + y)

0.6 x + 0.9 y = 7 (x + y)

0.6 x + 0.9 y = 0.7 (x + y)