Problema Solution
One week, Shanell bought one pound of cashews and two pounds of pecans, and paid $2.40. The next week she bought four pounds of almonds and one pound o cashews, paying $3.60. A week later she bought three pounds of walnuts, one of cashews, and one pound of almonds ofr $2.10.
How much would she have to pay on her next trip to the grocery store if she were to buy one pound of each of the our different types of nuts?
Answer provided by our tutors
Let
c = the cost per pound of cashews
p = the cost per pound of pecans
a = the cost per pound of almonds
w = the cost per pound of walnuts
c + 2p = 2.40 follows b = (1/2)(2.40 - c)
4a + c = 3.60 follows a = (1/4)(3.60 - c)
3w + c + a = 2.10 follows w = (1/3)(2.10 - c - a)
plug a = (1/4)(3.60 - c) into w = (1/3)(2.10 - c - a):
w = (1/3)(2.10 - c - (1/4)(3.60 - c))
w = (1/3)(2.10 - c - 0.90 + (1/4)c)
w = (1/3)(1.20 - (3/4)c)
We add the 3 equations: b = (1/2)(2.40 - c), a = (1/4)(3.60 - c) and w = (1/3)(1.20 - (3/4)c)
b + a + w = (1/2)(2.40 - c) + (1/4)(3.60 - c) + (1/3)(1.20 - (3/4)c)
b + a + w = 2.5 - c
c + b + a + w = 2.50
Shanell would pay $2.50.