Geysers Old Faithful is a geyser in Yellowstone National Park. It is so named because of its regular eruptions for the past 100 years. An equation that can predict the approximate time until the next eruption is T = 12.4L + 32, where T is the time, in minutes, until the next eruption and L is the duration, in minutes, of the last eruption. Use this equation to determine the duration of the last eruption when the time between two eruptions is 63 min