Interview Q&A / Aptitude

1. How many 4-digit numbers can be formed using the digits 0, 1, 2, 3, 4 and 5 without repetition?

   300. The first digit cannot be 0, so it has 5 choices. The remaining three places use the other 5 digits: 5 x 4 x 3. Total = 5 x 5 x 4 x 3 = 300.

   BeginnerQuick answer1 min read
2. In how many distinct ways can the letters of the word BANANA be arranged?

   60. BANANA has 6 letters with A repeated 3 times and N repeated 2 times, so the count is 6! / (3! x 2!) = 720 / 12 = 60.

   BeginnerQuick answer1 min read