Cards numbered 1 through 30 are placed in a bag and shuffled. one card is chosen at random. what is the probability of randomly selecting a number less than or equal to 5 or a multiple of 7? a) 3/10; b) 1/15; c) 2/15; d) 1/30

I am pretty shore that the correct answer is 3/10 because  you can x out d because their has to be more than a 1 % chance so that one one is out.and c is wrong because it is still not possible to get a 2 out of 15 because in this type of problem their will not have 2 defrent sylables and c wrong because if it is impossible to get 2/15 so it will be impossible to get 1/15 so it leaves it with the correct answer ...which is a

(1/x + 1)^2 + 6 (1/x + 1) +5