Permutations And Combinations Question 260

Question: The sum of all 4 digit numbers that can be formed by using the digits 2, 4, 6, 8 (repetition of digits not allowed) is

Options:

A) 133320

B) 533280

C) 53328

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

  • Sum of the digits in the unit place is $ 6(2+4+6+8)=120 $ units. Similarly, sum of digits in ten place is 120 tens and in hundredth place is 120 hundreds etc. Sum of all the 24 numbers is $ 120(1+10+10^{2}+10^{3})=120\times 1111=133320 $ .