Latest problems - page 8

  1. Thunder and lightning
    lightning There was a glimpse of the sky and we hear a thunder in 4.5 seconds. The light spreads at 300,000 kilometers per second, so we can assume the flash instantly without delay. However, the speed of the sound is much smaller in the air one third of a kilomete
  2. Equation 15
    eq222_4 Solve equation with variables on both sides:
  3. 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?
  4. Brick weight
    bricks_2 Half the weight of a brick plus 20 pounds is equal to 1/3 the weight of the brick plus 30 pounds. How much does the brick weigh?
  5. Quadrangular pyramid
    komoly Calculate the surface area and volume of a regular quadrangular pyramid: sides of bases (bottom, top): a1 = 18 cm, a2 = 6cm angle α = 60 ° (Angle α is the angle between the side wall and the plane of the base.) S =? , V =?
  6. Bed time
    clock-night-schr_3 Tiffany was 5 years old; her week night bedtime grew by ¼ hour each year. If, at age 18, her curfew time is 11pm, what was her bed time when she was 5 years old?
  7. Hour salary
    usd_8 You work for 4 hours on a Saturday and 8 hours on Sunday. You also receive a $50 bonus. You earn $164. How much did you earn per hour?
  8. Pamela
    penize_48 Lara Pamela spends her salary of 3000 for food, clothing, recreation and savings, which are in the ratio of 48:20:15:37, respectively. How much does he spend for savings?
  9. Suzan
    children2_3 Susan's age will be after 12 years four times as much as twelve years ago. How old is Susan now?
  10. Number unknown
    plusminus_3 Adela thought the two-digit number, she added it to its ten times and got 407. What number does she think?
  11. Unknown numbers
    eq222_3 The sum of two consecutive natural numbers and their triple is 92. Find these numbers.
  12. Substitution
    eq1_5 solve equations by substitution: x+y= 11 y=5x-25
  13. Ľé sweets
    bonbons_12 There are 20 sweets in the bag. Some are chocolate, other coconuts, and the remaining marzipan. Chocolate is 4 times more than coconut. Marzipan's less than chocolate. How much is in a bag of coconut sweets?
  14. Mixed2improper
    zlomky_8 Write the mixed number as an improper fraction. 166 2/3
  15. Desks
    desks A class has 20 students. The classroom consists of 20 desks, with 4 desks in each of 5 different rows. Amy, Bob, Chloe, and David are all friends, and would like to sit in the same row. How many possible seating arrangements are there such that Amy, Bob, C
  16. Mystery number
    numbers2_38 A mystery number is between 800 and 920. No digits are the same. The difference of the number is 5. What is the mystery number?
  17. Bus 14
    bus27_9 Boatesville is 65.35 kilometers from Stanton. A bus traveling from Stanton is 24.13 kilometers from Boatesville. How far has the bus traveled?
  18. Tangent 3
    tangetns In a circle with centre O radius is 4√5 cm. EC is the tangent to the circle at point D. Segment AB IS THE DIAMETER of given circle. POINT A is joined with POINT E and POINT B is joined with POINT C. Find DC if BC IS 8cm.
  19. Ebay is not free
    usd_7 Be aware of ebay - if you sell something expensive, fee is painful. There are lot of space for classifieds and local exchange away from global ebay. Calculate ebay+paypal fee if you sale 3641 USD laptop. Formula for ebay fee is 0,30 + 10 % of total earning
  20. Simple equations
    enc2 Solve system of equations: 5x+3y=5 5x+7y=25

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