A standard pack of cards contains 52 cards, divided into 4 suits of 13 cards each. We are interested in finding the probability that the 3 cards that are dropped belong to different suits.
Total number of ways to choose 3 cards from 52 cards:
\[
\text{Total ways} = \binom{52}{3} = \frac{52 \times 51 \times 50}{3 \times 2 \times 1} = 22100
\]
Now, we need to find the number of favorable outcomes where the 3 cards belong to different suits. To do this:
1. Choose 3 different suits from 4 suits: \( \binom{4}{3} = 4 \)
2. For each chosen suit, select 1 card (13 options for each suit):
\[
\text{Ways to select cards from different suits} = 13 \times 13 \times 13 = 13^3 = 2197
\]
Thus, the number of favorable outcomes is:
\[
\text{Favorable outcomes} = 4 \times 13^3 = 4 \times 2197 = 8788
\]
Now, the probability that the 3 cards belong to different suits is the ratio of favorable outcomes to total outcomes:
\[
P = \frac{8788}{22100}
\]
\[
P = \frac{169}{425}
\]
Thus, the correct answer is (B).