The ph of a solution ranges from 0 to 14. an acid has a ph less than 7. pure water is neutral and has a ph of 7. the ph of a solution is given by ph = -logx where x represents the concentration of the hydrogen ions in the solution in moles per liter. find the ph if the hydrogen ion concentration is 1 x 10-1

Titus works at a hotel. part of his job is to keep the complimentary pitcher of water at least half full and always with ice. when he starts his shift, the water level shows 4 gallons, or 128 cups of water. as the shift progresses, he records the level of the water every 10 minutes. after 2 hours, he uses a regression calculator to compute an equation for the decrease in water. his equation is w –0.414t + 129.549, where t is the number of minutes and w is the level of water. according to the equation, after about how many minutes would the water level be less than or equal to 64 cups?