The law f(t) = -t2 + 6t + 15 represents the number of kilometers of congestion, as a function of time, registered in a city. With that, determine the maximum number of congestion in that city and the maximum time to reach this value.

Aplane is flying at 32,500 feet. it needs to rise to 36,000 feet in two stages.• in stage 1, it rises 5% of its initial altitude of 32,500 feet.• in stage 2, it rises at a rate of 125 feet per minute.how many minutes does it take for the plane to rise during stage 2?