Haruka hiked several kilometers in the morning. she only hiked 666 kilometers in the afternoon, which was 25\%25%25, percent less she had hiked in the morning. how many kilometers did haruka hike in all?

How many liters of peroxide should be added to 12 liters of an 8% peroxide solution so that the resulting solution contains 16% peroxide?   original added new amount of peroxide 0.96 liters x 0.96 + x amount of solution 12 liters x 12 + x 0.18 liter 1.14 liters 1.92 liters 2.10 liters