No used :- 1,2,3,4,5,6,7

no laying between = 100-1000

7×6×5=210

The number lying between 100 and 1000 can be formed with the digits 1, 2, 3, 4, 5, 6, 7 is:

To find the numbers that can be formed using the digits 1, 2, 3, 4, 5, 6, and 7 between 100 and 1000, we need to consider the different possibilities for each place value.

Hundreds place:
- The hundreds place can be filled with any of the digits from 1 to 7, except for 0 and 8 or 9, as these digits are not available.
- So, there are 7 options for the hundreds place.

Tens place:
- The tens place can be filled with any of the digits from 0 to 7.
- However, if the hundreds place is filled with 1, the tens place can only be filled with digits 0 to 6, as repeating 1 would result in a number less than 100.
- So, there are 7 options for the tens place if the hundreds place is not 1, and 6 options if the hundreds place is 1.

Ones place:
- The ones place can be filled with any of the digits from 0 to 7, except for the digit in the hundreds place.
- So, there are 6 options for the ones place.

Now, we can find the total number of possible numbers by multiplying the number of options for each place value.

- If the hundreds place is not 1: 7 options for hundreds place * 7 options for tens place * 6 options for ones place = 294 possible numbers.
- If the hundreds place is 1: 1 option for hundreds place * 6 options for tens place * 6 options for ones place = 36 possible numbers.

Therefore, the total number of numbers that can be formed using the digits 1, 2, 3, 4, 5, 6, and 7 between 100 and 1000 is 294 + 36 = 330.