The inhabitants of the island of jumble use the standard kobish alphabet ($20$ letters, a through t). each word in their languag

Question

3 years ago

11

The inhabitants of the island of jumble use the standard kobish alphabet ($20$ letters, a through t). each word in their languag

e is $4$ letters or less, and for some reason, they insist that all words contain the letter a at least once. how many words are possible?

Mathematics

1 answer:

rjkz [21] · Answer 1 · 2022-03-08T20:38:21+03:00

We know that

1. The number of all 4-letter words written using the alphabet of 20 symbols (from A to T) is
20^4=160,000

2. The number of all 4-letter words written using the alphabet of 19 symbols (from B to T) is
19^4=130,321

3. The difference represents exactly the number of all words of the inhabitants of the island of Jumble
difference=(160,000-130,321)= 29679.

the answer is
29679