To find the probability of a number being a multiple of either 3 or 13, we need to find the number of multiples of 3 or 13 among the first 30 natural numbers.
Multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30
Multiples of 13: 13, 26
Now, we need to find the total number of multiples of 3 or 13. However, we need to be careful not to count the number 30 twice since it is a multiple of both 3 and 13.
Total multiples: 10 + 2 - 1 = 11
The probability is given by the number of favorable outcomes (multiples of 3 or 13) divided by the total number of possible outcomes (first 30 natural numbers).
Probability = Number of favorable outcomes / Total number of possible outcomes
= 11 / 30
Therefore, the chance of selecting a number that is a multiple of either 3 or 13 is 11/30.
The correct answer is option C) 2/5.