# Logarithm + exponential function - math problems

#### Number of problems found: 23

• Logarithm
Determine the number whose decimal logarithm is -3.8.
• Exponential equation
In the set R solve the equation: ?
• Log
if ?, what is b?
• Exponential equation
Solve for x: (4^x):0,5=2/64.
• Exponential equation
Find x, if 625 ^ x = 5 The equation is exponential because the unknown is in the exponential power of 625
• Coordinate
Determine missing coordinate of the point M [x, 120] of the graph of the function f bv rule: y = 5x
• Sequence
Calculate what member of the sequence specified by ? has value 86.
• Car value
The car loses value 15% every year. Determine a time (in years) when the price will be halved.
• Geometric progression
In geometric progression, a1 = 7, q = 5. Find the condition for n to sum first n members is: sn≤217.
• Demographics
The population grew in the city in 10 years from 30000 to 34000. What is the average annual percentage increase of population?
• Decibel
By what percentage does the sound intensity increase if the sound intensity level increases by 1 dB?
• The city 3
The city has 22,000 residents. How long it is expected to have 25,000 residents if the average annual population growth is 1.4%?
• 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.
• Population
The town has 65,000 inhabitants. 40 years ago, there were 157,000. How many people will live in a city in 10 years if the population's average rate is as in previous years?
• If you 4
If you deposit \$2500 in an account paying 11% annual interest compounded quarterly, how long until there is the \$4500 in the account?
• If you 2
If you deposit \$4000 into an account paying 9% annual interest compounded monthly, how long until there is \$10000 in the account?
• Semiannually compound interest
If you deposit \$5000 into an account paying 8.25% annual interest compounded semiannually, how long until there is \$9350 in the account?
• Crystal
The crystal grows every month 1.2 permille of its mass. For how many months to grow a crystal from weight 177 g to 384 g?
• Microorganisms
The first generation of micro-organisms has a population of 13500 members. Each next generation is 11/10 times the previous one. Find out how many generations will reach at least three times members of the first generation.
• Exponential warm
Suppose that a body with temperature T1 is placed in surroundings with temperature T0 different from that of T1. The body will either cool or warm to temperature T(t) after time t, in minutes, where T(t)=T0 + (T1-T0)e^(-kt) . If jello salad with 30 degree

Do you have an interesting mathematical word problem that you can't solve it? Submit a math problem, and we can try to solve it.

We will send a solution to your e-mail address. Solved examples are also published here. Please enter the e-mail correctly and check whether you don't have a full mailbox.

Please do not submit problems from current active competitions such as Mathematical Olympiad, correspondence seminars etc...

Logarithm - math word problems. Exponential function - math word problems.