Answer:
3 pens
Step-by-step explanation:
Total expenditure (Price x Quantity) on pens & pencils = $30
Let pen quantity be = x , Let pencil quantity be = y
Given : Pen (x) price = 5 , Pencil (y) price = 1.5 , Pencils (y) = Pen (x) + 5
So, 5x + 1.5y = 30
5x + 1.5 (x + 5) = 30 → 5x + 1.5x + 7.5 = 30 → 6.5x + 7.5 = 30
6.5x = 30 - 7.5 → 6.5x = 22.5
x = 22.5 / 6.5 → x = 3.46 ≈ 3 pens