Where is shilpa's husband

Please solve it before u see the answer :

Shilpa is 21 years older than her son Raju. In 6 years from now Shilpa will be 5 times as old as Raju.

Question: Where's Shilpa's Husband?

(There IS a mathematical solution for this.. try it before scrolling down)

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Solution:

Shilpa (MOM 'M') is 21 years older than Raju (Child 'C ').

M = C + 21

In 6 years from now the mom will be 5 times as old as the child.

M + 6 = ( C + 6 ) x 5

C + 21 + 6 = ( C + 6) x 5

C + 27 = 5C + 30

-3 = 4C

C = -3/4

The child is -3/4 year old, that's -9 months. Child will be born in 9 months. So, now you know where is Shilpa's husband