Question

How many four-digit numbers can be formed using the digits 1, 2, 3, 5, 8 if repetition of
digits is not allowed ? How many of these are
(i) divisible by
(ii) divisible by 5
(iii) odd
(iv) between 2000 and 5000 ?​

Answer 1

Answer:

Therefore, there are 360 - 72 = 288(Option C) numbers possible such that 2 and 5 don't come together. There are 6 digits in total and we have to form a 4 digit number, hence that can be done in 6p4 ways.

Answer 2

Answer:

Correct option is

A

125

Step-by-step explanation:

If a 4-digit number is formed by using the digits 1,2,3,4,5 (repitition is allowed )

Thousands, Hundreds and Tens place can be filled up with 5 ways each.

So, a total of 5×5×5 ways to fill these three place.

Now, if the given numbers 1,2,3,4,5 are filled in the unit place, they will form 5 consecutive numbers, out of which only one is divisible by 6.

So, total 4-digit numbers divisible by 6 are 5×5×5×1=125

hope it works...