There were 3/7 as many notebooks as pencils being sold. Each notebook
cost $4 more than each pencil. The total amount received from the sale of
notebookswas $120 more the amount received from the sale of pencils.
The total amount received was $750.
(a) What was the total amount received from the sale of pencils?
(b) How many notebook and pencils were sold altogether?
(c) What was the cost of each notebook?
Let the number of pencils sold==P
The number of notebooks sold ==3/7P
Let the sale price of each pencil =S
The sale price of each notebook ==S + 4
3/7P * [S + 4] - P*S ==120..........................(1)
3/7P * [S + 4] + P*S==750...........................(2), solve for P, S
Use elimination to get:
P==175 - pencils sold
S ==9/5 ==$1.80 - sales price of each pencil
(a) 175 x $1.80 ==$315 - amount received from sale of pencils
(b) 175 + 3/7*175==175 + 75 ==250 - total pencils and notebooks sold.
(c) $1.80 + $4.00 ==$5.80 - cost of 1 notebook.