The whole number which does not have a predecessor in whole number system is

1. 0

2. 1

3. 2

4. none of these

The predecessor of the smallest 4-digit number is

1. 99

2. 999

3. 1000

4. 1001

The product of the predecessor and the successor of the greatest 2-digit number is

1. 9900

2. 9800

3. 9700

4. none of these

The sum of the successor of the greatest 3-digit number and the predecessor of the smallest 3-digit number is

1. 1000

2. 1100

3. 1101

4. 1099