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?

The number of minutes that would make the water level be less than or equal to 64 cups is;160 minutes. We are given the equation;W = -0.414t + 129.549where; t is the number of minutesW is the level of waterThe expression to find the amount of time it will take for the water level be less than or equal to 64 cups is; -0.414t + 129.549 ≤ 64 Using substitution property of equality, subtract 129.549 from both sides to get;-0.414t + 129.549 - 129.549 ≤ 64 - 129.549-0.414t ≤ -65.549Using division property of equality, divide both sides by -0.414 to get;t ≤ -65.549/-0.414t ≥ 158.33(sign changed to ≥ because we divided the inequality by a negative number.)We have to approximate the inequality to get;t = 160 minutes. Read more about Inequalities at;