Question

A university bookstore recently sold a wirebound graph-paper notebook for $1.64, and a college-ruled notebook for $1.17. At the start of spring semester, a combination of 50 of these notebooks were sold for a total of $66.02. How many of each type were sold?

Answer 1

amount of graph paper sold = X

Answer 2

amount of college-ruled sold = Y

Answer 3

ok

Answer 4

the total cost of graph paper notebook sold is going to be 1.64 * X
the total cost of college ruled notebook sold is going to be 1.17 * Y

Answer 5

X + Y = 50 (total sold)

Answer 6

1.64 * X + 1.17 * Y = 66.02

Answer 7

solve for X and Y, and you're good to go.

Answer 8

this is how i set it up too

Answer 9

oh great! do you need help with how to solve it?

Answer 10

yes

Answer 11

lets mutliply the first equation (x+y = 50) by 1.17

Answer 12

you get 1.17x + 1.17y = 58.5

Answer 13

subtract the second equation (1.68x + 1.17y = 66.02) by the new equation

Answer 14

oh, i mean 1.64x + 1.17y = 66.02 no wonder it wasn't working when i was doing it by myself

Answer 15

so subtract the new equation (1.17x + 1.17y = 58,5) from that equation

Answer 16

ok i was wondering were that number came from

Answer 17

ok so you get 0.47x = 7.52

Answer 18

divide both sides by 0.47, and you get x = 16

Answer 19

plug this into the first equation of x + y = 50, and you get y = 34

Answer 20

so you sold 16graph paper notebooks and 34 college ruled notebooks.

Answer 21

thank you

Answer 22

no problem.:)