Examples for 8th grade - page 40

  1. Equations
    p1110617 Solve following system of equations: 6(x+7)+4(y-5)=12 2(x+y)-3(-2x+4y)=-44
  2. Logs
    tramy The log has diameter 30 cm. What's largest beam with a rectangular cross-section can carve from it?
  3. A three-digit numbers
    clocks_1 Determine the total number of positive three-digit numbers that contain a digit 1.
  4. Mother and daughter 2
    mother_baby The mother is 40 years older than her daughter. How old is the mother if her age is eight thirds age of daughter?
  5. Football league
    football_1 In the 4th football league plays each of the 16 participants with each opponent twice. For every victory gets 3 points, 1 point for a draw, a defeat none. After the competition was team with 56 points and 8 defeats at 6th place. How many times have won?
  6. Vectors
    vectors Vector a has coordinates (7; 16) and vector b has coordinates (15; -7). If the vector c = b - a, what is the magnitude of the vector c?
  7. Tachometer
    tatra-dakar2 Tatra's tachometer shows the initial state 154009 km this morning. Tatra today travel at an average speed of 35 km/h. Determine the function that describes the Tatra's tachometer depending on the time. What is the state of tachometer after 4.8 hours?
  8. Ice cream in cone
    Ice-Cream-Cone In the ice cream cone with a diameter of 3.6 cm is 0.9 dl of ice cream. Calculate the depth of the cone.
  9. Bridge
    bridge_circle The bridge arc has a span 41 m and height 3 m. Calculate the radius of the circle arc of this bridge.
  10. Tank
    barrel_1 In the middle of a cylindrical tank with a bottom diameter 350 cm is standing rod which is 31 cm above the water surface. If we bank rod its end reach surface of the water just by the tank wall. How deep is the tank?
  11. Freedom
    family_life In the city are 2/6 of women married for 4/4 men. What proportion of the townspeople is free (not married)? Express as a decimal number.
  12. Fraction
    polynomial For what x expression ? equals zero?
  13. Felix
    astronaut Calculate how much land saw Felix Baumgartner after jump from 22 km above ground. The radius of the Earth is R = 6378 km.
  14. Raffle
    tombola_tickets In the pool is numbers from 1 to 135. What is the probability that a randomly selected number is not a prime number?
  15. Euler problem
    euler Someone buys a 720 tolars towels. If it was for the same money of 6 more towels, it would be 6 tolars cheaper each. How many were towels?
  16. Trees
    jablone Along the road were planted 250 trees of two types. Cherry for 60 CZK apiece and apple 50 CZK apiece. The entire plantation cost 12,800 CZK. How many was cherries and apples?
  17. Coach
    hokej_4 Average age of 24 players and a coach of one team is 24 years. The average age of players without a coach is 23 years. How old is the coach?
  18. Linear system
    vahy_eq Solve this linear system (two linear equations with two unknowns): x+y =36 19x+22y=720
  19. Football season
    ball_f Dalibor and Adam together scored 97 goals in the season. Adam scored 9 goals more than Dalibor. How many goals scored each?
  20. Jam
    dzem Jar with jam weighs 800 grams. Jam weighs three times as much as the empty glass. What is the weight of jam that is in the glass?

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