A and b are two vectors and |a| = 3. Find the value of |a+b| when: (i) b = 2a
(ii) b = -3a
(iii) b is perpendicular to a and |b| = 4

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?

Write the equations in logarithmic form 9^4=6,561

The length of the line segment ac is 8x-9 what is the value of x