How many digits 2^400 has?
Choices:
A) 31  B) 35  C) 50  D) 99  E) 121
2^10 = 1.024 * 10^3 =&gt; 2^100 = (1.024)^10 * 10^120   therefore 121 digits would be my best guess   121
<result>E</result>
How many digits 2^400 has?