A dealer paid Php480 for some crates of potatoes. Eight crates spoiled and had to be discarded, but he sold the rest at an increase price of Php3 per crate, gaining Php40. How many crates did he buy?

Question

dumbcow · Answer

Let x be the number of crates, p be the price paid per crate 
xp = 480
(x-8)(p+3) = 480+40
____________________
solve using substitution
From 1st equation
p = 480/x
-> (x-8)((480/x)+3) = 520
distribute
480 +3x -3840/x - 24 = 520
set equal to zero
3x -64 - 3840/x = 0
Multiply equation by x to eliminate x in denominator
3x^2 -64x - 3840 = 0
Use quadratic formula
Ignore negative solution
x = 48
Therefore, he originally bought 48 crates at 10Php per crate

P.S. what is Php? what currency?

anonymous · Answer

Thank you! thats a lot of help
Php is Philippine peso :)

dumbcow · Answer

ahh, your welcome