Maths

posted by .

Sam used cement and sand to prepare a mixture. The ratio of the number of pails of cement used to the number of pails of sand used was 1:2. Sam then added 8 more pails of cement and the ratio became 5:2.
A.) How many pails of cement was used at first?
B.) How many pails of sand was used?

  • Maths -

    original amount of cement = x
    original amount of sand = 2x

    new amount of cement = x + 8
    new amount of sand = 2x

    (x+8)/(2x) = 5/2
    cross-multiply
    10x = 2x + 16
    8x = 16
    x = 2

    A) original amount of cement = 2 pails
    B) original amount of sand = 4

    check:
    new amount of cement = 2+8=10
    new amount of sand = 4

    10: 4 = 5:2

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Algebra

    A batch of concrete is made by mixing 1 part cement, 2.5 parts sand, and 3.5 parts gravel. How many pounds of sand and gravel are needed to make 300 pounds of cement?
  2. Math

    A contractor requires a cement mix that is 70% sand and 30% cement. He has 700 kg of a cement mix that is 80% sand and 20% cement. How much cement should he add so that he gets the required mix?
  3. Math,Ratio

    mr kim mixes cement&sand to make a mixture.he uses 2 pails of cement for every 5 pails of sand. a) if he uses 24 pails of cement,how many pails of sand does he use?
  4. Math

    Mr Kim mix cement and sand to make a mixture.He uses 2 pails of cement for every 5 pails of sand. (A) Find the ratio of the number of pails of cement to the number of pails of sand. (B) If he uses 24 pails of cement,how many pails …
  5. 6th grademath plz help

    Each pail of plaster covers 90 square feet of ceiling. What is the least number of pails of plaster you would need to buy to cover the ceiling of a room with walls 14 feet long?
  6. Math

    Each pail of plaster covers 90 square feet of ceiling. What is the least number of pails of plaster you would need to buy to cover the ceiling of a square room with walls 14 feet long?
  7. Math

    concrete is to be mixed using cement and sand into the ratio 2:5. how much sand will be required to mix with 96 pounds of cement?
  8. Maths

    Matilda is looking at making a concrete mix. She mixes 2 parts of cement powder to every 7 parts of sand. Cement costs 35 cents a kilogram and sand costs 20 cents a kilogram. In total she spent $180. What was the total weight of cement …
  9. Mathmatics Asap Please!!!!!

    Susanna is going to make some concrete, using cement, sand and gravel, in the ratio 1:3:3. Nicola wants to make 245kg of concrete. There is 40kg of cement, 110kg sand and 105kg gravel. Is there enough material to make concrete. Thank …
  10. mathematical literacy

    Brick layers makes mortal with cement lime sand and water in the ratio of 1:1:5:1 if they have 2bucket of lime, how much should they use for cement, sand and water?

More Similar Questions