Math

Mr. Badger bought 12 pens every month until their price rose to 15 cents each. Now he can only afford to buy 10 pens at the same total cost as before. What was the original price of each pen?

There are 41 pigs and chickens on a farm. If there are 100 legs counted altogehter, how many of each animal are there?

One day, 5/6 of the office staff came to work. If three more had been away, this fraction would have decreased to 3/4. How many people are on full staff?

Mrs. Grant was 20 when her eldest child, tess, was born. Carly was born 2 years later and Troy another 4 years later. Now the average of their four ages is 39. How old are Mrs. Grant and her three children?

Please help...

asked by Crissy XD
  1. 2. We have X pigs and Y chickens.
    Eq1: X + Y = 41 Pigs and chicken.

    Each pig has 4 legs and each chicken has 2 legs:
    Eq2: 4X + 2Y = 100 Legs.

    Multiply both sides of Eq1 by -2 and
    add the 2 Eqs:

    -2X - 2Y = - 82,
    4X + 2Y = 100,

    2X = 18,
    X = 9 Pigs.

    Substitute 9 for X in Eq1:
    9 + y = 41,
    Y = 41 - 9 = 32 Chickens.

    3. 5X/6 - 3 = 3X/4,
    Multiply both sids by 12:
    10x - 36 = 9X,
    10X - 9X = 36,
    X = 36 Staff members.

    4. Tess: X Years old.
    Mrs. Grant: X+20.
    Carly: X-2.
    Troy: X-6.

    (X + (X+20) + (X-2) + (X-6)) / 4 = 39,
    (4X + 12) / 4 = 39,
    Multiply both sides by 4:
    4X + 12 = 156,
    4X = 156 - 12 = 144,

    X = 36 = Tess's age.
    X+20 = 36+20 = 56 = Mrs. Grant's age.
    X-2 = 36-2 = 34 = Carly's age.
    X-6 = 36-6 = 30 = Troy's age.



    posted by Henry

Respond to this Question

First Name

Your Response

Similar Questions

  1. 10th Grade Math

    Mr. Badger bought 12 pens every month until their price rose to 15 cents each. Now he can only afford to buy 10 pens at the same total cost as before. What was the original price of each pen? There are 41 pigs and chickens on a
  2. WORD PROBLEMS W/ EQUATIONS

    Mr. Badger bought 12 pens every month until their price rose to 15 cents each. Now he can only afford to buy 10 pens at the same total cost as before. What was the original price of each pen? There are 41 pigs and chickens on a
  3. Maths Year 10 Equations

    A shopkeeper bought x pens for $21. a) write down an expression, in terms of x, for the cost, in cents, of each pen b) the shopkeeper gave 2 pens to his sons and sold each of the remaining pens at 8 cents more than he paid for it.
  4. Math

    In a store, pencils have one price and pens have another. 3 Pencils and 2 pens cost 78 cents. 2 pencils and 3 pens cost 72 cents. How much does 1 pencil and 1 pen cost? Help! I don't get this.
  5. Algebra

    A box contains blue and purple pens. There are 6 less than triple the number of blue pens as purple pens. A blue pen costs 20 cents and a purple pen cost 35 cents. The total value of all the pens is $37.90. How many of each colour
  6. Math

    answer in the box. The Students' Union need to order some pens and notebooks. How much does it cost to order 1000 pens and 2000 notebooks? $ Cost Effective Pen Quantity 100 250 500 1000 2500 5000 Price per pen (cents) 80c 72c 66c
  7. math

    John bought a total of 30 white and brown pens for a total of $32. The cost of each white pen is 70 cents more than the cost of each Brown pen. Which would be the possible value of the cost of each Brown pen( in cents)? Please
  8. Math

    I bought three times as many erasers as pens and spent $155 in total. I spent $65 more on the pens than the erasers. Given that 's pen cost $1.90 more than an eraser, find the cost of a pen.
  9. math

    2x + 3y = 78 How do i solve for x and y? 2x=78 78/2=39 so x=39 3y=78 78/3=26 so y=26 Can't be, because 2(39)+ 3(26) does not equl 78 You need TWO equations when you have TWO variables, such as x and y. It can't be done with one
  10. math

    With 300 dollars one will have to buy total 30 items. If price of a exercise book is 30 dollars, price of pen is 24 dollars and price of a pencil is 6 dollars, and if that person is bound to buy at least one of each item, how many

More Similar Questions