Problem Solving

Hi all,

I am struggling a little bit with the concept of weighted averages.

A certain stationary store sells pencils for $2 and pens for $3. If the average price of pens and pencils sold in a certain day is $2.60, how many pens were sold?

To get the exact number of pens sold, you would need to know the total number of pens and pencils sold, correct?

But how do you determine the ratio of pens to pencils sold with only the above information?

Thank you!

Questions seems to be incomplete

but we can surely determine the ratio here
suppose
no. of pencils sold = x
no. of pens sold = y
equate the average now
(2x + 3y)/(x+y) = 2.6
=> 2x + 3y = 2.6x + 2.6y
=> .4y = .6x
=> x/y = 2/3

Yes, you only know the ratio (as calculated above) to get the number you would need more information.

Great-thank you for the responses. I was not sure how to calculate the ratio from the information given.