Logarithm - math problems

Number of problems found: 50

Logarithm
Determine the number whose decimal logarithm is -3.8.
Seating rules
In a class are 24 seats but in 7.B class are only 18 students. How many ways can students sit? (The class has 12 benches. A bench is for a pair of students.) Result (large number) logarithm and thus write down as powers of 10.
Log
if ?, what is b?
Powers 3
2 to the power of n divided by 4 to the power of -3 equal 4. What is the vaule of n?
Sequence
Calculate what member of the sequence specified by (5^n-2+15) has value 20.
Log
Calculate value of expression log |3 +7i +5i²| .
Exp
If sqrt[7](20²-12²) = sqrt[n](256), then n is:
Exponential equation
Solve for x: (4^x):0,5=2/64.
Radioactivity
After 548 hours decreases the activity of a radioactive substance to 1/9 of the initial value. What is the half-life of the substance?
Exponential equation
In the set R solve the equation: ?
What is
What is the annual percentage increase in the city when the population has tripled in 20 years?
Intercept with axis
F(x)=log(x+4)-2, what is the x intercept
Gain
Find the gain whenever the output power is 21x the input power.
Logarithmic equation
Solve equation: log₁₃(7x + 12) = 0
Dice
How many times must throw the dice, the probability of throwing at least one six was greater than 90%?
Car value
The car loses value 15% every year. Determine a time (in years) when its price will halve.
Compound interest
Calculate time when deposit in the bank with interest 2.5% p.a. doubles.
Coordinate
Determine missing coordinate of the point M [x, 120] of the graph of the function f bv rule: y = 5^x
Sum-log
The sum of two numbers is 32, the sum of their logarithms (base 10) is 2.2. Determine these numbers.
An investment
How long will it take for an investment to double at a simple interest rate of 5.10% per annum? Express the answer in years and months, rounded up to the next month.

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