30 pens and 75 pencils were purchased for 450 . if the average price of a pencil was 2.00 , find the average price of a pen .
since average price of a pencil = 2 ∴ price of 75 pencils = 150 ∴ price of 30 pens = ( 450 – 150 ) = 300 ∴ average price of a pen = 360 ⁄ 60 = 10 answer a
divide(subtract(450, multiply(75, const_2)), 30)