AppliedNumeric answer
A four-character password is drawn from the 26 lowercase letters, repeats allowed. How many contain at least one vowel?
Answer with a number. Fractions, powers and expressions like 23/6 or C(52,5) are read correctly in practice.
The worked solution is in Premium
The answer, the full working and the one idea to take away – for this and all 1,322 questions in the bank. Answer it in practice and your working is marked, with a known mistake named when you make one.
Learn the method
Reported in interviews at
More counting and combinatorics questions
- How many ways can a committee of 3 be chosen from 8 people?Foundation
- A four-digit PIN allows repeated digits. How many are there?Foundation
- Five people sit in a row.Foundation
- What is the smallest group of people that guarantees at least three share a birth month?Foundation
- Six people sit at a round table.Foundation
- How many distinct arrangements are there of the letters of MISSISSIPPI?Foundation