How many passwords of 8 character can be made using the list of character {2,5,7,A, B,C, M,Z}, so that (repetition not allowed)
i) it always starts with either ‘2’ or ‘Z’ or ‘M’ and ends with a number
ii) never ends with ‘B’ and starts with a alphabet

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?