Eliza’s backpack weighs 18 and StartFraction 7 over 9 EndFraction pounds with her math book in it. Without her math book, her backpack weighs 14 and StartFraction 7 over 8 EndFraction pounds. How much does Eliza’s math book weigh? 3 and StartFraction 11 over 72 EndFraction pounds
3 and StartFraction 65 over 72 EndFraction pounds
4 and StartFraction 11 over 72 EndFraction pounds
4 and StartFraction 65 over 72 EndFraction pounds

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?