# Logarithm - examples

- Dice

How many times must throw the dice, the probability of throwing at least one three was greater than 90%? - Sequence

Calculate what member of the sequence specified by ? has value 643. - Exp

If ?, then n is: - Compound interest

Calculate time when deposit in the bank with interest 2% p.a. doubles. - Logarithmic equation

Solve equation: log_{11}(10x + 28) = 0 - Demographics

The population grew in the city in 10 years from 14000 to 27500. What is the average annual percentage increase of population? - Lion or virgin

We toss coin, every throw fits lion or a virgin with equal probability 1/2. Determine how much at least we have to make throws that with probability 0.9 lion fell at least once. - Crystal

Crystal grows every month 2.9 promile of its mass. For how many months to grow a crystal from weight 310 g to 482 g? - Logarithm

Determine the number whose decimal logarithm is -4.5. - Seating rules

In a class are 22 seats but in 2.B class are only 14 students. How many ways can student seat? (The class has 11 benches. A bench is for a pair of students.) Result (large number) logarithm and thus write down as powers of 10. - Half life

Determine the half life of bismuth, when bismuth weight from the original weight of 32 g was only 2 grams in 242 minutes. - Geometric sequence 3

In geometric sequence is a_{6}= 77760; a_{7}= 466560; s_{n}=93310. Calculate the first item a_{1}, quotient q and n - number of members by their sum s_n. - Coordinate

Determine missing coordinate of the point M [x, 108] of the graph of the function f bv rule: y = 3^{x} - Log

if ?, what is b? - When will I be a millionaire?

Chris monthly send 150 euros to the bank, which he deposits bear interest of 2.1% p.a. Calculate how many months must Chris save to save 1000000 euros? Inflation, interest rate changes or bank failures ignore. - Gain

Find the gain whenever the output power is 11x the input power. - Car value

The car loses value 15% every year. Determine a time (in years) when the price will be halved. - Radioactivity

After 115 hours decreases the activity of a radioactive substance to 1/9 of the initial value. What is the half-life of the substance? - Future of libraries

You know that thanks to the Internet, electronic communications and developing online resources on the Internet annually declining number of traditional readership by 15%. These deal is irreversible evolutionary shift from old books from libraries to immed - Exponential equation

Solve exponential equation (in real numbers): 12^{-x-10}=18

Do you have interesting mathematical example that you can't solve it? Enter it and we can try to solve it.