Pls explain the best way u can

Abarge can safely haul no more than 400 tons across the river. the barge has an empty weight of 24 tons. the average weight of the railroad cars is 4 tons each.bhow many railroad cars can the barge haul?

4. jake needs to score in the top 10% in order to earn a physical fitness certificate. the class mean is 78 and the standard deviation is 5.5. what raw score does he need? z value for top 10% =1.282 how do i get the z value? what is the equation for this? raw score =mean+z*sd = 78+1.282*5.5 = 85.051

Customers are used to evaluate preliminary product designs. in the past, 93% of highly successful products received good reviews, 51% of moderately successful products received good reviews, and 14% of poor products received good reviews. in addition, 40% of products have been highly successful, 35% have been moderately successful and 25% have been poor products. round your answers to four decimal places (e.g. 98.) what is the probability that a product attains a good review? (b) if a new design attains a good review, what is the probability that it will be a highly successful product? (c) if a product does not attain a good review, what is the probability that it will be a highly successful product?