A class used cars and vans to go on a field trip because all of the buses were already in use. They used 15 vehicles to go on the trip. Each car holds 4 students and each van holds 6 students. If 74 students went on the trip, then how many of each type of vehicle did the class use?

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?