A perfect cube that is divisible by 7 ,when that number contain a cube of 7 or a perfectÂ
multiple of 7's cube in following form , $$N=7^3\times k^3\ \left(where,\ k=1,2,3.....\right)$$
If we, put k=6 ,then the number become, $$N=7^3\times6^3=74088.$$
But , if we put k=7, then the number become, $$N=7^3\times7^3=117649.$$
117649 exceeds 100000 , So there are only 6 numbers(when, k=1,2,....,6) present between 1 and 100000 which are divisible by 7.
B is correct choice.
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