Question

The cost of packing a box of chocolates is given by 1/4x^2, where x is the number of chocolates (a box can never have fewer than 3 chocolates). If the weight of a box of chocolates is given by x + 2, what is the cost of packaging per weight unit?

A) 1/4x - 1/2+ 1/x+2 (all fractions)
B) 1/4x^2 - 1/2x +1
C) 1/4x^2 - 1/2 +1
D) 1/4x - 1/2 - 1/x+2

Answer 1

@jigglypuff314

Answer 2

@Zarkon
Can you help me please.

Answer 3

@zepdrix

Answer 4

knowing that x is greater than or equal to 3, you can start plugging in x values (3,4,5,etc) and seeing which of the answers matches.

For example : x=3 :

\[0.25*3^{2}\] = the cost of packaging

the weight will be 3+2 = 5

Therefore, per unit of weight it will be

\[9/4 \div 5 = 9/20\]

If you plug in your x value to the answers, you get

\[3/4 - 1/4 + 1/5 = (15-10+4)/20 = 9/20\]

\[3^{2}/4 - (3+1)/2 = 9/4 + 4/2 = 9/4 + 8/4 = 17/4\]

\[3^{2}/4 - 1/2 + 1 = 9/4 - 2/4 + 4/4 = 11/4\]

\[3/4 - 1/2 - 1/(3+2) = 3/4 - 2/4 - 1/5 = 1/4 - 1/5 = 5-4/20 = 1/20 \]

for each of the respective answers. Since A is the only one that yielded a correct answer, it must be A. You can verify this with other x values.

Answer 5

Thanks