A number is chosen at random from1 to 10. Find the probability of not selecting a multiple of 2 or a multiple of 3

Which equation and solution can be used to solve this problem? thirteen less than a number is sixteen. 13-n=16: add 13 to both sides. the answer is 29. n+13=16: subtract 13 from both sides. the answer is 3. n+16=13 subtract 13 from both sides. the answer is 3. n-13=16: add 13 to both sides. the answer is 29.

Me because some of question i don’t understand

What is the similarity ratio of a cube with volume 729m^3 to a cube with volume 3375 m^3