I know this has already been asked, but it doesnt actually have an answer, so can some one solve it? Technetium-99m is used as radioactive tracer for certain medical tests. It has a half-life of 1 day. Consider the function T where T(d) = 100(2)^-d is the percent of technetium-99m remaining d days after the test. Which expression represents the number of days until only 5% remains?
A) log20 2.
B) -log2 20.
C) log2 (1/20).
D) -log2 (1/20).​

Nell has a sales clerk job that pays $12 per hour for regular gas work hours. she gets double time for any hours over 40 that she works in a week. how many hours did nell work if her weekly pay was $744

Needmax 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.

21 a stick 7 inches long is broken into two pieces, so that one piece is twice as long as the other one. how long are the two pieces?