Question

A vendor sells hot dogs and bags of potato chips. A customer buys 3 hot dogs and 3 bags of chips for $10.50. Another customer buys 2 hot dogs and 4 bags of chips for $9.50. Find the cost of a hot dog

Answer 1

Let's us suppose the cost of 1 hot dog is x and the cost of 1 potato chip is y.

`3x+3y=10.5 ------ Equation 1`

`2x+4y=9.5 ------- Equation 2`

Now if we multiply equation 1 by 2 and equation2 by 3, and subtract equation 1 from second we have:

Equation 1 will become :

6x+6y=21

Equation 2 will become:

6x+12y=28.5

Now subtracting above two, we have:

6x+12y=28.5

6x+6y=21

6y=7.5

y=1.25

Now lets us substitute the value of y=1.25 in equation 1:

then we have:

3x+3(1.25)=10.5

x=2.25

Therefore the cost of a hot dog is $2.25