Permutations And Combinations Question 275

Question: How many numbers less than 1000 can be made from the digits 1, 2, 3, 4, 5, 6 (repetition is not allowed)

Options:

A) 156

B) 160

C) 150

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

  • Number of 1 digit numbers $ {{=}^{6}}P_1 $ Number of 2 digit numbers $ {{=}^{6}}P_2 $ Number of 3 digit numbers $ {{=}^{6}}P_3 $ The required number of numbers $ =6+30+120=156 $ .