4. There are 40 litres of water in a barrel.
The water flows out of the barrel at a rate of 125 millilitres per second.
1 litre = 1000 millilitres.
Work out the time it takes for the barrel to empty completely.

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?