Question

using divisibility test,determine which of the following number are divisible by 3,5,6,9....
$options \: \\ a)726352 \\ b)21084v \\ c)2150 \: \\ d)6000$

Answer 1

divisibility rule of 3 = if the sum of the number is divisible by 3 the number is divisible

rule of 5 = if the number ends in 0 or 5, it will be divisible by 5

rule of 6 = if the number is divisible by both 2 and 3 then the number will be divisible by 6

rule of 9 = if the sum of the digits is divisible by 9 then number will be divisible by 9

(i) 726352 sum of the digits = 25,

so this number cant be divisible by 3 and when it cant be divisible by 3 then wont be divisible by 6 either. There is no 0 or 5 at the end so 5 cant divide it and sum of the digits cant be divided by 9 so the number is not divisible by 9 also.

this number is not divisible by any of 3,5,6,9

(ii) 21084 sum of the digits = 15

this number is divisible by 3,6

(iii) 2150 sum of the digits = 8

this number can only be divisible by 5

(iv) 6000 sum of the digits = 6

this number can only be divisible by 3,6,5