David can unload a delivery truck in 20 min. allie can unload the same delivery truck in 35 min. if they work together, how long will the unloading take?

Asap describe the transformations required to obtain the graph of the function f(x) from the graph of the function g(x). f(x)=-5.8sin x. g(x)=sin x. a: vertical stretch by a factor of 5.8, reflection across y-axis. b: vertical stretch by a factor of 5.8,reflection across x-axis. c: horizontal stretch by a factor of 5.8, reflection across x-axis. d: horizontal stretch by a factor of 5.8 reflection across y-axis.

In a test for esp (extrasensory perception), a subject is told that cards only the experimenter can see contain either a star, a circle, a wave, or a square. as the experimenter looks at each of 20 cards in turn, the subject names the shape on the card. a subject who is just guessing has probability 0.25 of guessing correctly on each card. a. the count of correct guesses in 20 cards has a binomial distribution. what are n and p? b. what is the mean number of correct guesses in 20 cards for subjects who are just guessing? c. what is the probability of exactly 5 correct guesses in 20 cards if a subject is just guessing?

How many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.) how many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.)