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Andrew and Cutter were assigned to buy refreshments for the History Club meeting

ID: 3120402 • Letter: A

Question


Andrew and Cutter were assigned to buy refreshments for the History Club meeting. They bought the same items in the following amounts: Andrew: 3 six-packs of drinks, 2 bags of chips, and 4 packages of cookies, for a total cost of $22.00. Cutter: 2 six-packs of drinks, 4 bags of chips, and 5 packages of cookies, for a total cost of $26.30. After the meeting, Madeline agreed to buy the unused items at the purchase cost. She got 1 six-pack of drinks, 2 bags of chips, and 4 packages of cookies, for a total cost of $17.20. Find the cost of each item.

Explanation / Answer

Solution: Let price of six pack drinks = x,

price of bags of chips = y and

price of packages of cookies = z

now according to the problem the equations are

3x+2y+4z=22---- 1

2x+4y+5z=26.30 ------2

and

x+2y+4z=17.20 -------3

Now subtracting 3 from 1

i.e. 3x+2y+4z-(x+2y+4z) = 22-17.20

3x+2y+4z-x-2y-4z = 4.8

2x = 4.8

x = 2.4

now put x = 2.4 in equation 1 and 2

so equation 1 - -> 3x+2y+4z = 22

3(2.4)+2y+4z = 22

7.2+2y+4z = 22

2y + 4z = 14.8 ---4

For equation 2 - ->

2x+4y+5z=26.30

4.8+4y+5z=26.30

4y+5z=21.5---5

multiply equation 4 with number 2 we get

2(2y+4z) = 59.2

4y+8z = 29.6--6

Subtract 5 from 6

4y+8z-4y-5z=8.1

3z=8.1

z=2.7

Put this value in 5

we get

4y+5z=21.5

4y+5(2.7) = 21.5

4y+13.5=21.5

4y=8

y=2.