Question

Tell a number which if kept upside down and is increased by 9 gives 1000

Answer 1

166= on upside down 991+9 =1000

Answer 2

The answer is 661.

The digit 6 when turned upside down becomes the number 9. However, the digit 1 when turned upside down remains the same. So, when the number 661 is turned upside down, it becomes 991. When this number is increased by 9 (991 + 9), the answer is 1,000.