Answer :
largest 7 digit number=9999999
smallest 8 digit number=10000000
difference=10000000-9999999=1
smallest 8 digit number=10000000
difference=10000000-9999999=1
Largest 7 digit number is 9999999....
Smallest 8 digit number is 10000000....
Difference will be 10000000-9999999= 1..