Question

find the number of digit 25^20×18^50​

Answer 1

Answer:

        The number has 91 digits

Step-by-step explanation:

Taking logarithms base 10:

• log 1 = 0
• log 10 = 1
• log 100 = 2
• log 1000 = 3
• etc

And for in-between numbers, the logs are in-between, too, so:

• log (one digit number) = 0.something
• log (two digit number) = 1.something
• log (three digit number) = 2.something
• etc

In general, the number of digits is just one more than the number before the decimal point.

So...

 log (25²⁰ × 18⁵⁰)  =  20 log 25  +  50 log 18  ≈  90.722

tells us that the number 25²⁰ × 18⁵⁰ has 91 digits.

Hope that helps.