The place value of number 7 is = (7×1000) = 7000

The Remaining number is: 12 when 1000 divided by 19

when 3100 divided by 17 = 6 ( Remaining)

Intended number = 13q + 1 and q = 5Q + 3,

Intended number = 13 × (5Q + 3) + 1 = 65Q + 40.

The remainder when dividing that number by 65= 40.

Number to be added = x.
First 3 digit number = 116.
(116 + x) Must be completely divisible by 8, so the number added is 4.

17 numbers are less than 1 to 35 numbers and 18 numbers are odd.
Therefore, n(n + 1) = 17( 17 + 1) = 206.

unit digit = 3 + 4 + 7 +1 = 15. Hence unit number is 5.

70405009

x + y = 15, x - y = 7.
15 + 7 divided by 2 gives 11, Similarly 15 -7 divided by 2 hives 4. 11 × 4 = 44