A concession stand sold a total of 58 sodas and chips. A soda costs $2.50, and chips costs $2.00. Total sales were 135. How many chips were sold.

Question

can be solved any way you like.

Answer 1

s = number of sodas sold

c = number of chips sold

cost of soda = 2.50 per soda

cost of chips (bag) = 2.00 per chip (bag)

Equations:

"sold a total of 58 sodas and chips"

s + c = 58

"total sales were 135"

2.50s + 2.00c = 135

Use substitution to solve:

c = 58 - s

2.5s + 2.0(58-s) = 135

2.5s + 116 - 2s = 135

2.5s -2s + 116 = 135

0.5s + 116 = 135

0.5s = 19

s = 38 = number of sodas sold

Plug s = 38 into formula:

c = 58 - s

c = 58 - 38

c = 20 = number of chips

plug into other formula to check:

2.5(38) + 2(20) = 135

95 + 40 = 135

135 = 135 yes!

Answer 2

s = number of soda

c = number of chips

Since a total of 58 sodas and chips were sold, we can write that in an equation form: s + c = 58.

Next, we are given the prices of each items: sodas are $2.50 and chips are $2.00.

We combine this information with the next; "total sales were 135".

The total sales for sodas is 2.50s (2.50 multiplied by s); the sales for chips is 2.00c.

Hence, 2.50s + 2.00c = 135 (or 2.5s + 2c = 135)

Since the problem is asking for the number of chips (c), we simultaneously solve the two equations

s + c = 58

2.5s + 2c = 135

Because we want "c=..." we eliminate the variable s.

One method is substitution: substitute s = 58 - c from the first equation to the second equation's s.

2.5 (58 - c) + 2c = 135

Then solve:

145 - 2.5c + 2c = 135 (combine like terms)

145 -0.5c = 135 (subtract 145 from both sides of the = sign)

-0.5c = -10 (divide -0.5 from both sides)

c = -10/-0.5 = 20

The answer is 20 chips.