HMMT 十一月 2014 · 冲刺赛 · 第 8 题
HMMT November 2014 — Guts Round — Problem 8
题目详情
英文原题
- [ 7 ] Find the number of digits in the decimal representation of 2 .
解析
英文解析
- [ 7 ] Find the number of digits in the decimal representation of 2 .
Answer: 13 Noticing that 2 = 1024 ≈ 1000 allows for a good estimate. Alternatively, the 10
number of decimal digits of n is given by ⌊ log ( n ) ⌋ + 1. Using log (2) ≈ 0 . 31 also gives the correct
10 10
answer. The exact value of 2 is 2199023255552.41