Question

If 1 is added to the greatest 7- digit number, it will be equal to(A) 10 thousand (B) 1 lakh (C) 10 lakh (D) 1 crore

Answer 1

It's quite easy.

First, largest 7 digit number is --?
Its 9,999,999
Now, add 1 to it
9,999,999 + 1 = 10,000,000
or
in Indian numbering system - 1,00,00,000

Its (d) one crore

Answer 2

we know that the greatest 7 digit number is 99,99,999
so adding 1, it will become 1,00,00,000 
this is 1 crore