In the last month, the ratio between Davis's monthly expenditure and his monthly salary was 3 : 7. What percentage of his monthly income did he save last month?

Atemperature of 1.64◦f corresponds to answer in units of ◦c.

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?

Solve the following pair of equations for x and y: ax/b_ by /a= a +b; ax - by = 2ab