What is 3/4 divided by 1/2

Which letters from the table represent like terms? a and b b and c a and d b and d

If you flip a coin 3 times, what is the probability of flipping heads 3 times? a. p(3 heads) = 3/8 b. p(3 heads) = 1/6 c. p(3 heads) = 1/8 d. p(3 heads) = 1/2

How can you find the mean absolute deviation (mad) for this set of data?