8999 of them.
24
17
3 digit numbers are lessthan 4 digit numbers
-2
There are 90 such numbers.
The first 3 digit natural number is 100: 100 ÷ 4 = 25 → first 3 digit natural number divisible by 4 is 4 × 25 The last 3 digit natural number is 999: 999 ÷ 4 = 249 r 3 → last 3 digit natural number divisible by 4 is 4 × 249 → number of 3 digit natural numbers divisible by 4 is 249 - 25 + 1 = 225.
24
17
3 digit numbers are lessthan 4 digit numbers
There are 2941 4-digit numbers such no two of its digits differ by 1.
There are 16 4-digit numbers that can be made up from 9 and 6.
-2
12 numbers
There are 90 such numbers.
90
9999
24