Question

What is the divisibility rule of 7 when a number has 4 - digits

Answer 1

follow the steps :
1. double the unit digit of a given no.
2. subtract the above no. from the no . formed by excluding the unit digit of the given no .
3. if the no . so obtained is divisible by 7 then the given no. is divisible by 7.

ex- the given no. is 1067
now, 106 -(2×7)= 106-14 = 92 , which is not divisible by 7 , hence 1067 is not divisible by 7.