Question 1037331
8 oz * 0.96=7.68
x oz*0.76=0.76x
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8+x*(0.80)=6.4+0.80x. That equals the sum of the above, or 7.68+0.76x.
Therefore, 0.04x=1.28
x=32 oz.
Check: Four times as much 76% must be used, and 80% is four times closer to 76% than it is to 96%.