Time - high school - math problems

Number of problems found: 299

  • 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%?
  • Weighted harmonic average
    workers Ten workers will do some work in 2 minutes, five workers in 10 minutes and three workers in 6 minutes. How many minutes per average worker per worker?
  • RC time constant
    capacitor You introduced 1 Coulomb worth of electrons into the inner volume of a dielectric material with ϵr=6. Thirty minutes later, you found that only 36.79% of the electrons were in the internal volume. Determine the conductivity σ of the dielectric material.
  • Up and down motion
    ballistic We throw the body from a height h = 5 m above the Earth vertically upwards v0 = 10 m/s. How long before we have to let the second body fall freely from the same height to hit the Earth at the same time?
  • This year
    calendar This year 2020 is a leap year. How many leap years there had been be since 1904?
  • Journey to spa
    car Mr. Dvorak took his wife to the spa, and the journey took 3.5 hours. On the way back, he drove 12 km/h faster and was home in 3 hours. At what speed did he go to the spa, and at what speed did he return?
  • When I
    age When I am as old as my older brother is today, my brother will be twice as old as I am today. a) How old is my brother if I am 8 years old today? b) How old am I if my brother is 21 today?
  • Part-time workers
    mince Three part-time workers received CZK 1,235 for their work. The first received 20% less than the second and the third received 45 CZK more than the second. Determine how many crowns (CZK) each of them received.
  • 2 cyclists and car
    cyclist One cyclist rides at a constant speed over a bridge. It is 100 meters long. When he is 40 meters behind him, he meets an oncoming cyclist who is riding at the same speed. The car travels along the bridge in the same direction as the first cyclist at a spe
  • Candles
    sviecka Before Christmas, Eva bought two cylindrical candles - red and green. Red was 1 cm longer than green. She lit a red candle on Christmas Day at 5:30 p. M. , lit a green candle at 7:00 p. M. , and left them both on fire until they burned. At 9:30 p. M. , bo
  • Birthday paradox
    holland How large must the group of people be so that the probability that two people have a birthday on the same day of the year is greater than 90%?
  • Slow saving in banks
    penize How long will it take to save € 9,000 by depositing € 200 at the beginning of each year at 2% interest?
  • Percentage increase
    exp_growth2 What is the annual percentage increase in the city when the population has tripled in 20 years?
  • Quiz or test
    test I have a quiz with 20 questions. Each question has 4 multiple choice answers, A, B, C, D. THERE IS NO WAY TO KNOW THE CORRECT ANSWER OF ANY GIVEN QUESTION, but the answers are static, in that if the "correct" answer to #1 = C, then it will always be equal
  • 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?
  • A particle
    integral_speed A particle moves in a straight line so that its velocity (m/s) at time t seconds is given by v(t) = 3t2-4t-4, t>0. Initially the particle is 8 meters to the right of a fixed origin. After how many seconds is the particle at the origin?
  • Energy consumption
    elektromer The device is connected to 230V and draws 3.5A current. Power consumption is 1932kJ. How many minutes has this device been in operation?
  • 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
  • Working together
    workers Two people will do the work in 12 days. They worked together for 8 days. Then only one worked for 10 days. How many days would each of them do the work if he worked alone?
  • The tourist
    eq2 The tourist wanted to walk the route 16 km at a specific time. He, therefore, came out at the necessary constant speed. However, after a 4 km walk, he fell unplanned into the lake, where he almost drowned. It took him 20 minutes to get to the shore and re

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