Melissa is interviewing for a job in the suburb of another city and decides that the best way to get there is to fly to the city and take a train to the suburb. if the plane is on time 90% of the time and the train is on time 70% of the time, what is the probability that both will be on time?

There are 13 diamonds and 13 hearts = 26 red cards
The combinations of 5 objects taken from 26 object 

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.