Problema Solution

Carl needs to buy exactly 100 pieces of candy and only spend $9.00 The following is the cost of the candy:

Jawbreakers 2 for .5 cents

Lollipops .10 cents each

Chocolate bars .20 cents each

How many pieces of each candy does Carl need to buy?

Answer provided by our tutors

let


2x = the number of Jawbreakers since they are sold in a pair, x>0

y = the number of lollipops, y>0

z = the number of chocolate bars, z>0


2x + y + z = 100 => x<=50, y <= 100, z<=100


he can only spend $9 = 900 cents


0.5*x + 0.10*y + 0.20*z = 900


since x<=50, y <= 100, z<=100 we have


0.5*x + 0.10*y + 0.20*z <= 0.5*50 + 0.10*100 + 0.20*100 = 55 < 900


thus the system


2x + y + z = 100

0.5*x + 0.10*y + 0.20*z = 900


where x, y and z are non-negative integers has no solutions


Carl can not buy 100 candies and spend $9.