So you need to set up something called a proportion. You should know what that is. With the ratio(fraction) 5-out-of-6, followed by an equal sign(=), and then the fraction(read carefully!) 6-out-of-n. N is your denominator. Now perform Means and Extremes, or cross multiplying. Multiply 5*n to get 5n. Multiply 6*6 to get 36. Now you need to isolate the variable from 5. Divide 5n to get 'n', and divide 36/5 to get 7.5. You end up with n=7.5. The value of n is 7.5, and that is your answer. To check, replace n with 7.5 in the proportion. Cross multiply to get the two numbers. If equivalent, then congrats, you have the right answer!