Ascientist has two solutions, which she has labeled solution a and solution b. each contains salt. she knows that solution a is 70 % salt and solution b is 95 % salt. she wants to obtain 80 ounces of a mixture that is 80 % salt. how many ounces of each solution should she use?

Let x represent the number of ounces of 95% salt she should use.

Then the total amount of salt in the 80 ounces of solution is ...

... 0.95x + 0.70(80-x) = 0.80·80

... 0.25x = 64 -56 . . . . . . . collect terms, subtract 56

... x = 8·4 = 32 . . . . . . . . . . multiply by 4

She should use 32 ounces of 95% salt and (80-32=) 48 ounces of 70% salt,

hey! so 1 (25) out of 4 (100) is 25 so your answer is 25%. it's like quarters!