Question 1075878
This can be done a few ways.  Since it's a small number, we'll do it the easiest way - estimation.
What is the maximum number of pens that can be bought for $28?  28/4 = 7
That's not enough items.  What if we buy 6? 6*4 = 24.  That leaves us 2 items short.  2*2 = 4.  24+4=28.  
6 pens and 2 pencils