<PRE><B>Question 1141187</B>
 3/5 of the number of pens displayed at the bookstore were red and the rest were blue.
let p = total no. of pens
then
{{{3/5}}}p = no. of red pens
and
{{{2/5}}}p = no. of blue
:
After 260 red pens, and 1/4 of the blue pens were sold, 1/2 of the pens were left.
260 + {{{1/4}}}*{{{2/5}}}p = {{{1/2}}}p
260 + {{{2/20}}} = {{{1/2}}}p
reduce fraction
260 + {{{1/10}}}p = {{{1/2}}}p
get rid of denominator, multiply by 10
2600 + p = 5p
2600 = 5p - p
2600 = 4p
p = 2600/4
p = 650
:
How many pens were displayed at the bookstore first? 650</PRE>