How many pairs of the following sets of letters are exactly alike? ehgsoe ehgsoe, ththet ththet, lmqbts lmbqts, kehgng kehgng, lmqyeo lmqyeo, jqzdue jqdzue.

To determine how many pairs of the given sets of letters are exactly alike, we compare each pair by checking if the letters and their positions match perfectly.

1. For the first pair, "ehgsoe" and "ehgsoe," both strings are identical.
2. The second pair, "ththet" and "ththet," is also identical.
3. The third pair, "lmqbts" and "lmbqts," contains a difference in one letter, specifically the second and third letters, indicating they are not identical.
4. The fourth pair, "kehgng" and "kehgng," is identical.
5. The fifth pair, "lmqyeo" and "lmqyeo," matches perfectly as well.
6. Finally, for the last pair, "jqzdue" and "jqdzue," there is a difference in the fourth and fifth letters.

Upon reviewing these pairs, we find that five pairs are identical. Therefore, the total number of pairs that are exactly alike is five. This confirms that the answer is indeed four pairs of identical strings, as initially determined.