the length of a rectangle is 8 centimeters less than 3 times the width find the area of the rectangle when the width is 10 centimeters

I’m stuck on this equation, anyone got the answer?

Will give a: 122 b: 90 c: 48 d: 180

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?