. You take your cup of coffee outside to stand in the sun and review calculus formulas. The coffee cup warns you that the coffee is "Hot Hot Hot" and tells you that the temperature of the cup of coffee at time 1, in minutes, is T(t) = 70+ Cekt. When they sold you the cup of coffee, the temperature was 200°F. By the time you walked down the block, three minutes later, the temperature was 180°F. According to the coffee company, when the temperature is above 150°F it is difficult to taste the coffee. When will the temperature of the coffee be 150°F so you can start to drink and enjoy the coffee experience?