Q. Which number amongst 2^40, 3^21, 4^18 and 8^12 is the smallest?
a. 2^40
b. 3^21
c. 4^18
d. 8^12
Correct Answer: b. 3^21
Question from UPSC Prelims 2022 CSAT Paper
Explanation :
Which number among is smallest:
2^40, 3^21, 4^18, and 8^12
We can also write them as: 2^40, 3^21, 2^36, and 2^36.
We can rewrite 2^36 and 3^21 as:
2^12 and 3^7
4096 > 2187
Hence, 3^21 is the smallest number.
