Permutations and Combinations 3 Question 8
8. The number of 5 digit numbers which are divisible by 4 , with digits from the set ${1,2,3,4,5}$ and the repetition of digits is allowed, is
(2018 Adv.)
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Answer:
Correct Answer: 8. (625)
Solution:
- A number is divisible by 4 if last 2 digit number is divisible by 4 .
$\therefore$ Last two digit number divisible by 4 from $(1,2,3,4,5)$ are $12,24,32,44,52$
$\therefore$ The number of 5 digit number which are divisible by 4 , from the digit $(1,2,3,4,5)$ and digit is repeated is
$ 5 \times 5 \times 5 \times(5 \times 1)=625 $
