If 4 cards are drawn from a deck of 52 cards and not replaced. Find the probability of getting at least 1 black card.

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.

It would take her 20 minutes.

4x 20 is 80 but if ther machine is broken then there is none you have to redo the test