Problema Solution
A jumbo chocolate bar with a rectangular shape measures 15 centimeters in length, 8 centimeters in width, and 2 centimeters in thickness. Due to escalating costs of cocoa, the management has decided to reduce the volume of the bar by 20%. To accomplish this reduction, management decides that the new bar should have the same 2 centimeter thickness, but the length and width of each should be reduced by an equal number of centimeters. What should the the dimensions of the new candy bar?
Answer provided by our tutors
volume of orginal = 15*8*2 = 240 cu.cm.
reduced volume = 240 - 20% of 240 = 240 - 48 = 192cu.cm.
let reduction in each length and width be x cm.
(15-x)(8-x)*2 = 192
120-23x-x^2 = 96
x^2 +23x-24 = 0
(x+23)(x-1) = 0
x=1,-23
reduction in length and width = 1cm