Permutations And Combinations Question 286

Question: How many numbers can be made with the digits 3, 4, 5, 6, 7, 8 lying between 3000 and 4000 which are divisible by 5 while repetition of any digit is not allowed in any number [RPET 1990]

Options:

A) 60

B) 12

C) 120

D) 24

Show Answer

Answer:

Correct Answer: B

Solution:

  • 3 must be at thousand place and since the number should be divisible by 5, so 5 must be at unit place. Now we have to filled two place (ten and hundred) i.e., $ ^{4}P_2=12 $ .