A water trough is 10m long and a cross-section has the shape of an isosceles triangle that is 50 cm wide at the top and 50cm high. If the trough is being filled with water at the rate of 4000 cm3/min, how fast is the water level rising when the water is 30 cm deep?.

The weekly amount spent by a company for travel has an approximately normal distribution with mean = $550 and standard deviation = $40. a) what is the probability that the actual weekly expense will exceed $570 for more than 20 weeks during the next year? (note: one year = 52 weeks) b) what is the probability that actual weekly expenses exceed $580 for 10 or more, but 16 or fewer weeks during the next year?