SOLUTION: How many digits are in the number 5^72 * 2^74 ?

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Question 269362: How many digits are in the number 5^72 * 2^74 ?

Found 2 solutions by Edwin McCravy, stanbon:
Answer by Edwin McCravy(20064) About Me  (Show Source):
You can put this solution on YOUR website!
How many digits are in the number 5%5E72+%2A+2%5E74 ?


1%2A10%5E0=1 through 9%2A10%5E0=9 has 1 digit.
1%2A10%5E1=10 through 9%2A10%5E1=90 has 2 digits.
1%2A10%5E2=100 through 9%2A10%5E2=900 has 3 digits.
1%2A10%5E3=1000 through 9%2A10%5E3=9000 has 4 digits.
1%2A10%5E4=10000 through 9%2A10%5E4=90000 has 5 digits.
     ...
1%2A10%5En=10000%22...0%22 through 9%2A10%5En=9000%22...0%22 has n+1 digits.

So we see the pattern here that the power of 10 in any scientific
notation is one less than the number of digits.  Therefore, 



has 73 digits. 

Edwin

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
How many digits are in the number 5^72 * 2^74 ?
---
10^72*2^2
= 4x10^72
---
# of digits = 73
=========================
Cheers,
Stan H.