Algebra - problems - page 86

  1. Digit sum
    cisla_7 How many are three-digit numbers that have a digit sum of 6?
  2. The sides
    rectangle_9 The sides of a rectangle are in a ratio of 2:3, and its perimeter is 1 1/4 inches. What are the lengths of its side? Draw it.
  3. Subsets
    venn5 How many 19 element's subsets can be made from the 26 element set?
  4. Calculate
    equilateral_triangle2 Calculate the length of a side of the equilateral triangle with an area of 50cm2.
  5. Sponsor
    tenis_2 The children of the tennis school received 64 white and 48 yellow balls from the sponsor. When asked about how many balls they could take, they were answered: "You have so many that none of you will have more than 10 balls and all will have the same number
  6. Geometric progression
    exp_1 In geometric progression, a1 = 7, q = 5. Find the condition for n to sum first n members is: sn≤217.
  7. Sum of inner angles
    angle-sum-of-polygon Prove that the sum of all inner angles of any convex n-angle equals (n-2) . 180 degrees.
  8. Girls
    skola_10 The boys and girls in the class formed without the rest of the fives, 2 girls and 3 boys. There are 6 girls missing to create mixed pairs (1 boy and 1 girl). How many girls are in the classroom?
  9. Guppies
    guppies Audrey has some guppies in a fish tank. The ration of the oranges guppies to silver guppies is 3:5. She has 12y oranges guppies. Write the number of silver guppies she has in terms of y
  10. Six-sided polygon
    hexagon-irregular In a six-sided polygon. The first two angles are equal, the third angle is twice (the equal angles), two other angles are trice the equal angle, while the last angle is a right angle. Find the value of each angle.
  11. Meat loses
    maso_3 Meat loses 18% of its weight by smoking. How much raw meat butcher used to manufacture 35 kilos of smoked?
  12. Father 7
    family_8 Father is 6 times older than his son. After 4 years, the father will only be 4 times older. What are their present ages?
  13. Square into three rectangles
    stvorcove-cisla_1 Divide the square with a side length of 12 cm into three rectangles with have the same circumference so that these circumferences are as small as possible.
  14. Pexeso
    paper_3 Drawing paper has dimensions of 60cm and 840mm. Pupils have to divide it into squares so that they can make a pexeso. What dimension must squares have if their side is to be larger than 3cm and less than 10cm?
  15. Find two
    eq222_7 Find two consecutive natural numbers whose product is 1 larger than their sum. Searched numbers expressed by a fraction whose numerator is the difference between these numbers and the denominator is their sum.
  16. Combinations 6
    dices2_3 6 purses 9 flaps 12 straps Every combination must include 1 purse, 1 flap and 1 strap. How many possible combinations?
  17. Clothes
    dvojice_2 Danka and Janka collect clothes. Danka had 9 more than Janka, so she gave her 7. Which now has more cloth and how many?
  18. Simple equations
    enc2 Solve system of equations: 5x+3y=5 5x+7y=25
  19. The price
    map_16 The price of the land increased by 17%. What was the original price of the land if it now costs 46800 €?
  20. Cinema tickets
    listky Cinema sold 180 tickets this Thursday, which is 20%. Monday 14%, Tuesday 6%, Wednesday 9%, Friday 24%, Saturday 12%, and Sunday 15%. How many tickets were sold per week?

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