David scored x marks for his mathematics test, edwin scored 4/5 of what david scored. frank scored 38 marks more than edwin and gabriel scored 5 fewer marks than frank.
(a) express gabriel's marks in terms of x.
(b) if the average mark of the four boys is 64.5, find gabriel's marks for the mathematics test.

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

Now max recorded the heights of 500 male humans. he found that the heights were normally distributed around a mean of 177 centimeters. which statements about max’s data must be true? a) the median of max’s data is 250 b) more than half of the data points max recorded were 177 centimeters. c) a data point chosen at random is as likely to be above the mean as it is to be below the mean. d) every height within three standard deviations of the mean is equally likely to be chosen if a data point is selected at random.

Aubrey read 29 books and eli read 52 books what number is equal to the number of books aubrey read?