What is the value of x in the triangle

There are a total sales of 2,000 dollars on monday on tuesday sales dropped 10% on wednesday sales dropped another 20% compared with tuesday from wednesday to thursday sales increases by an equal amount to 25% of monday total sales what is the net change in dollars on total sales from monday to tuesday

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?

How many four digit even numbers can be formed from digits 1,2,3,4,5 if repetition is allowed. how can solve this using permutation formula