Question

The number of natural numbers lying between 1012 and 23421 that can be formed using the digits 2,3, 4, 5, 6 (repetition of digits is not allowed) and divisible by 55 is

Answer 1

Answer: 6

4 digit numbers

$a+c=b+5$
$\text{ for }b=1a=2,c=4$
$a=4,c=2$
$\text{ for }b=2a=3,c=4$
$a=4,c=3$
$\text{ for }b=3a=6,c=2$
$a=2,c=6$
$\therefore 6$ possible four digit no.s are div. by 55
(II) 5 digit number is not possible