Geometric progression + time - math problems

Number of problems found: 39

  • Annual growth
    exp_growth2 The population has grown from 25,000 to 33,600 in 10 years. Calculate what was the average annual population growth in%?
  • The half life
    exp_growth2 The half-life of a radioactive isotope is the time it takes for a quantity of the isotope to be reduced to half its initial mass. Starting with 145 grams of a radioactive isotope, how much will be left after 3 half-lives?
  • Savings
    500eur The depositor regularly wants to invest the same amount of money in the financial institution at the beginning of the year and wants to save 10,000 euros at the end of the tenth year. What amount should he deposit if the annual interest rate for the annua
  • Volume of wood
    wood Every year, at the same time, an increase in the volume of wood in the forest is measured. The increase is regularly p% compared to the previous year. If in 10 years the volume of wood has increased by 10%, what is the number p?
  • Growth of wood
    wood The annual growth of wood in the forest is estimated at 2%. In how many years will make the forest volume double?
  • Five harvests
    zrno In the seed company, they know that, out of 100 grains of a new variety, they get an average of 2000 grains after harvest. Approximately how many grains do they get out of 100 grains after five harvests?
  • Pilsen circus
    cirkus The arrival of the circus in Pilsen was seen in the morning at 08:00 by a city citizen. He passed this information on 08:15 to three other residents of the city. Each of these three people then informed the other three residents at 08:30, and again at 08:
  • Pilsen Region
    exp_growth Between 2000 and 2001, 14 per mille of the population decreased in the Pilsen Region. In 2000, the Pilsen Region had 551281 inhabitants. If the declining trend continues the same (i. E. , 14 per mille of inhabitants per year), how many inhabitants will th
  • Six speeds
    gears-3 A drilling machine is to have 6 speeds ranging from 50 to 750 revolutions per minute. If the speed forms a geometric progression, determine their values.
  • Investment 2
    exp_growth2 Jack invested $5000 in a 5-month term deposit at 4.7% p. A. . At the end of the 5-months, jack reinvested the maturity value from the first deposit into an 11-month term deposit at 7.3% p. A. What is the maturity value at the end of the second term deposi
  • Curiosity factor
    wwww A blogger starts a new website, initially the number of the traffic is 293 due to their curiosity factor. The business owner estimated that the traffic will increase by 2,6% per week. What will be the number of it in week 5?.
  • The machine
    mince The annual depreciation of the machine is 10%. After 8 years, the machine is worth 697 euros. What was the price of this machine at the time of purchase?
  • Microorganisms
    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.
  • The crime
    crime The crime rate of a certain city is increasing by exactly 7% each year. If there were 600 crimes in the year 1990 and the crime rate remains constant each year, determine the approximate number of crimes in the year 2025.
  • Compound interest
    bank Compound interest: Clara deposited CZK 100,000 in the bank with an annual interest rate of 1.5%. Both money and interest remain deposited in the bank. How many CZK will be in the bank after 3 years?
  • Population
    population What is the population of the city with 3% annual growth, if in 10 years the city will have 60,000 residents?
  • To the cinema
    tree 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
  • Miraculous tree
    tree Miraculous tree grows so fast that the first day increases its height by half the total height of the second day by the third, the third day by a quarter, etc. How many times will increase its height after 6 days?
  • The city 2
    kingkong Today lives 298000 citizens in the city. How many citizens can we expect in 8 years if their annual increase is 2.4%?
  • Half life
    Bi Determine the half life of bismuth, when bismuth weight from the original weight of 32 g was only 2 grams in 242 minutes.

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