# Number Properties Puzzle – Challenge 12

This is a great logic puzzle and brain teaser for those who enjoy solving math and critical thinking problems. Let’s see how you solve it! The solution is also provided.

## Challenge:

How many digits are used to write the number $$20^{10}$$?

A- 10

B- 11

C- 12

D- 13

E- 14

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The correct answer is E.

$$20^{10} = (2 × 10)^{10} = 2^{10 }× 10^{10 }= 1024 × 10^{10}$$
1024 has four digits and $$10^{10 }$$ has 11 digits. Why?
Therefore, $$20^{10 }$$ has 15 digits.