Answer:
Answer. 105 ounces of water is needed.
Let W = the volume of water to be mixed in ounces).
Then the volume of the 30% salt solution needed is (210-W).
The balance equation for the salt mass is
0.3*(210-W) = 0.15*210.
Simplify and solve for W:
63 - 0.3W = 31.5,
63 - 31.5 = 0.3W,
0.3W = 31.5,
W = 31.5%2F0.3 = 105.
Answer. 105 ounces of water is needed.
Step-by-step explanation: