The probability that it rains in London on any particular day is 0.3. If it rains then the probability of it raining the following day decreases to 0.25. Consider the next two days. What is the probability it doesn't rain on either day?

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.