Grade - examples - page 175

  1. Tractors
    tractor_5 Two tractors plow the field in 4 hours together. If the first tractor plow half of the field and then the second tractor completed the job, it would take 9 hours. How many hours does the field plow for each tractor separately?
  2. Sequence 11
    sequence_geo_2 What is the nth term of this sequence 1,1/2,1/3,1/4,1/5 ?
  3. The third
    meter_16 The one-third rod is blue, one-half of the rod is red, the rest of the rod is white and measures 8 cm. How long is the whole rod?
  4. Volume of cube
    cubes2_1 Solve the volume of a cube with width 26cm .
  5. Balls groups
    gulky_5 Karel pulled the balls out of his pocket and divide it into the groups. He could divide them in four, six or seven, and no ball ever left. How little could be a ball?
  6. Two pumps
    pumps_4 Pump A takes twice as long to fill a tank than B . Together they take 2 hours to fill the tank. How long does each one take to fill the tank by itself?
  7. Dice
    dices2_5 We throw 10 times a play dice, what is the probability that the six will fall exactly 4 times?
  8. Four workers
    wood_6 Four workers will lay the floor of the gym in six hours. After an hour of working together, one of the workers left to the doctor. How long before the remaining three workers finish their work?
  9. Equilateral cylinder
    sphere_in_cylinder A sphere is inserted into the rotating equilateral cylinder (touching the bases and the shell). Prove that the cylinder has both a volume and a surface half larger than an inscribed sphere.
  10. Glass panel
    glass_4 A rectangular glass panel with dimensions of 72 cm and 96 cm will cut the glazier on the largest square possible. What is the length of the side of each square? How many squares does the glazier cut?
  11. Bricklayers
    delnik_4 When a bricklayer works himself to redeem the house in 8 days, the other bricklayer will be finished in 10 days. How long will it take to make 3 such houses together?
  12. ABCD square
    s1 In the ABCD square, the X point lies on the diagonal AC. The length of the XC is three times the length of the AX segment. Point S is the center of the AB side. The length of the AB side is 1 cm. What is the length of the XS segment?
  13. Turners
    workers_25 Two turners perform joint work in 3 hours. The first turner would perform the job himself in 7 hours. How long would the same job last for a second turner if he worked alone?
  14. Lcm of three numbers
    prime What is the Lcm of 120 15 and 5
  15. Money 6
    penize_41 Lita had some money. She spent 1/2 of it on a hand bag and 1/3 of the remainder of the blouse. She had 260.00. How much money did she have at start?
  16. The work
    clock-night-schr_17 The work was to be done by 150 workers. At the beginning of their work, their number reduced by 40, which increased the time of work by 5 and 1/3 of the schedule. How long did work take?
  17. Performance
    workers_42 Two masons with the same performance would have made of plaster for 6 days. One of them, however, has increased its daily performance by 50%. How long would take they now to make plaster together?
  18. Equilateral triangle
    vpisany_stvorec A square is inscribed into an equilateral triangle with a side of 10 cm. Calculate the length of the square side.
  19. 3 children
    cukr_2 3 children had to divide 4 pounds is candy. How much candy did each child get?
  20. Parcel 4
    usd_3 To send a parcel by messenger within city limits costs 60 cents for the first pound and 48 cents for each additional pound. What is the cost, in cents, of sending a parcel weighing p=4 pounds?

Do you have an interesting mathematical example that you can't solve it? Enter it, and we can try to solve it.

To this e-mail address, we will reply solution; solved examples are also published here. Please enter e-mail correctly and check whether you don't have a full mailbox.