(UPSC CSAT – 2023)
- 855
- 856
- 910
- 911
Solution: Ans.(2.)
Every non-zero digit (1, 2, 3, 4, 5, 6, 7, 8, 9) appears 20 times in all the integers from 1 to 99.
19 times in all the integers from 10 to 99.
Sum of all digits appear in the integers from 10 to 99 is = (1×19 + 2×19 + 3×19 + 4×19 + 5×19 + 6×19 + 6×19 + 7×19 + 8×19 + 9×19) = 45 × 19 = 855
Sum of all digits appear in the integers from 10 to 100 is = 855+1 = 856
Video Solution:
