Exponential equation - examples
- Geometric progression
In geometric progression, a1 = 7, q = 5. Find the condition for n to sum first n members is: sn≤217.
- Water lilies
Water lilies are growing on the pond and their number is doubled every day. The whole layer is covered in 12 days. How many days will it cover 8 layers?
Crystal grows every month 2.2 promile of its mass. For how many months to grow a crystal from weight 160 g to 311 g?
- When will I be a millionaire?
Shawn monthly send 220 euros to the bank, which he deposits bear interest of 2.4% p.a. Calculate how many months must Shawn save to save 1000000 euros? Inflation, interest rate changes or bank failures ignore.
- Compound interest
Calculate time when deposit in the bank with interest 2.5% p.a. doubles.
The population grew in the city in 10 years from 42000 to 54500. What is the average annual percentage increase of population?
- Geometric sequence 3
In geometric sequence is a8 = 312500; a11= 39062500; sn=1953124. Calculate the first item a1, quotient q and n - number of members by their sum s_n.
If ?, then n is:
Calculate what member of the sequence specified by ? has value 86.
- 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.
- Computer revolution
When we started playing with computers, the first processor, which I remember was the Intel 8080 from 1974, with the performance of 0.5 MIPS. Calculate how much percent a year rose CPU performance when Intel 486DX from 1992 has 54 MIPS. What
The sum of two numbers is 32, the sum of their logarithms (base 10) is 2.2. Determine these numbers.
What is the annual interest rate on your account if we put 32790 and after 176 days received 33939.2?
- Exponential equation
In the set R solve the equation: ?
- To the cinema
Jane at 8 am got message that all 1093 school pupils will go to the cinema. Within 20 min she said it to the three friends. Each of them again for 20 minutes said to the other three. In this way the message spread further. At what time all the children in.
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
Solve exponential equation (in real numbers): 98x-2=9
Determine missing coordinate of the point M [x, 120] of the graph of the function f bv rule: y = 5x
- Car value
The car loses value 15% every year. Determine a time (in years) when the price will be halved.
- 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.