Question

A university bookstore recently sold a wirebound graph-paper notebook for $3.36, and a college-ruled notebook for $4.57. At the start of spring semester, a combination of 50 of these notebooks were sold for a total of $205.51. How many of each type were sold?

Answer 1

my formula is: b@y = (z - tx)/(y-x)

Answer 2

graphs @ 3.36 = (205.51 - 50(4.57))/(3.36-4.57)

might have to chop off a negative sign tho

Answer 3

google calculator says 19 :) so the rest would be colleged

Answer 4

sorry im confused

Answer 5

you need to be more specific; what are you confused about?

Answer 6

the normal long way to do this is to define the seperate amounts that total up to 50

a + b = 50

now write an equation that totals up the number of items times their prices that equal 205.51

ax + by = 205.51 ; and solve either by substitution or elimination

i eliminate..................

a + b = 50 <-- times by -x
ax + by = 205.51


-ax -bx = -50x
ax+by = 205.51
----------------
b(y-x) = (205.51 - 50x)

b@y = (205.51 - 50x)/(y-x)

Answer 7

determine what you want as b and what its price is; and fill in the restq

Answer 8

Ummm..amistre? That would be all well and good if the prices weren't already set. I think you're nuking this a bit.

Let a = number of graph-paper notebooks sold.
Let b = number of college-ruled notebooks sold.

a + b = 50
3.36a + 4.57b = 205.51

Solve the system...
a = 50-b

Substitue into 2nd equation

3.36(50-b) + 4.57b = 205.51
168.00 - 3.36b + 4.57b = 205.51
1.21b = 37.51
b = 31

So, a = 19.

19 graph-paper notebooks were sold and 31 college-ruled notebooks were sold.

Answer 9

ty makes more sense mtbender:)

Answer 10

i kept a and b; as well as x and y generic so that it wouldnt matter in the end.

if b = graphs at y = 3.36; then a = college at x = 4.57

or

if b = college at y = 4.57; then a = graphs at x = 3.36

Answer 11

I kept up with you, but given the nature of the question, I thought yoyokris wasn't tracking :) I did like your generic formula...took me back to Business Calculus :)

Answer 12

yay!! :)

Answer 13

its hard to tell what yoyok is or is not tracking since the only response is "im confused" ...