Question

On a recent trip to the convenience​ store, you picked up 4 gallons of​ milk, 5 bottles of​ water, and 8 ​snack-size bags of chips. Your total bill​ (before tax) was ​$33.60. If a bottle of

water costs twice as much as a bag of​ chips, and a gallon of milk costs ​$1.90 more than a bottle of​ water, how much does each item​ cost?

Answer 1

One gallon of milk costs $3.64

One bottle of water costs $2.54

One bag of chips costs $0.79

Explanation:

m represent gallons of milk

w represents bottles of water

c represents snack-size bags of chips

t = total bill

t = m + w + c ... eq 1

t = $33.60

but

w = 2c

m = 1.90 + w

m = 1.9 + 2c

Slot in the values in eq 1

33.60 = (1.9 + 2c ) + 2c + c

33.60 = 1.9 + 5c

33.60 - 1.9 = 5c

31.7 = 5c

c = $6.34

Slot in the value of c in w and m

w = 2c

w = 2(6.34)

w = $12.68

m = 1.9 + 2c

m = 1.9 + 2(6.34)

m = $14.58

4 gallons of milk cost $14.58

Therefore, one gallon if milk costs = 14.58/4 = $3.64

5 bottles of water cost $12.68

Therefore, one bottle of water costs = 12.68/5 = $2.54

8 bags of chips = $6.34

Therefore, one bag of chips cost = 6.34/8 = $0.79