Examples for 8th grade - page 94

  1. How far
    lighthouse_1 From the top of a lighthouse 145 ft above sea level, the angle of depression of a boat 29°. How far is the boat from the lighthouse?
  2. Candy
    friends Peter had a sachet of candy. He wanted to share with his friends. If he gave them 30 candies, he would have 62 candies. If he gave them 40 candies, he would miss 8 candies. How many friends did Peter have?
  3. Unknown numbers
    eq222_3 The sum of two consecutive natural numbers and their triple is 92. Find these numbers.
  4. Rhombus construction
    rhombus_7 Construct ABCD rhombus if its diagonal AC=9 cm and side AB = 6 cm. Inscribe a circle in it touching all sides...
  5. Surface of cubes
    cubes3_6 Peter molded a cuboid 2 cm, 4cm, 9cm of plasticine. Then the plasticine split into two parts in a ratio 1:8. From each part made a cube. In what ratio are the surfaces of these cubes?
  6. Clubhouse
    stol_2 There were only chairs and table in the clubhouse. Each chair had four legs, and the table was triple. Scouts came to the clubhouse. Everyone sat on their chair, two chairs were left unoccupied, and the number of legs in the room was 101. How many chairs w
  7. 6 terms
    arithmet_seq Find the first six terms of the sequence. a1 = 7, an = an-1 + 6
  8. Competitors
    ski_2 In the first round of slalom fell 15% of all competitors and in the second round another 10 racers. Together, 40% of all competitors fell. What was the total number of competitors?
  9. Fence and scale
    ctverec_mo_4 The garden with 80 m of fencing is draw on plan as a square with a side length of 4 cm. At what scale is this plan made?
  10. Five pumps
    nadrz_14 The water tank is filled with two pumps in 48 minutes. How long would it take to fill it with 5 same pumps?
  11. Trapezoid ABCD
    trapezium_2 ABDC is a trapezoid in which AB and CD are parallel sides measuring 6 and 9 respectively. Angles ABC and BCD are both right angles. Find the length of segment BD.
  12. Trapezium bases
    lichobeznik_7 Find the trapezium height if a = 8 cm and c = 4 cm if its content 21 square centimeters.
  13. Rhombus
    kosostvorec_1 The rhombus has diagonal lengths of 4.2cm and 3.4cm. Calculate the length of the sides of the rhombus and its height
  14. Lighthouse
    maiak The man, 180 cm tall, walks along the seafront directly to the lighthouse. The male shadow caused by the beacon light is initially 5.4 meters long. When the man approaches the lighthouse by 90 meters, its shadow shorter by 3 meters. How tall is the lightho
  15. Diamond diagonals
    kosostvorec Calculate the diamonds' diagonals lengths if the diamond area is 156 cm square and the side length is 13 cm.
  16. Square area
    100-square Complete the table and then draw each square. Provide exact lengths. Describe any problems you have. Side Length Area .
  17. Summands
    magic Find two summands of the number 42, so that its product is minimized.
  18. Percentages 5
    usd_1 $5.25 is 7 1/2% of what number?
  19. Road
    12perctent The angle of a straight road is approximately 12 degrees. Determine the percentage of this road.
  20. Digit sum
    number_line_3 The digit sum of the two-digit number is nine. When we turn figures and multiply by the original two-digit number, we get the number 2430. What is the original two-digit number?

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