How many letters does the longest word from this list contain?The longest word that's possible to assemble from the specified combination is 'gibbi', which contains 5 characters.
In total, how many words are possible to make using this combination of letters?From this list of words with 'gib' at the start and 'i' at the end, you have 2 entries that are available.
What is the highest scoring word in Scrabble with the above combination ?As there is just 2 combinations to pick from, your only viable choice is 'gibbi' which totals 10 points.