Question

Serenity and her children went into a movie theater and she bought $77.75 worth of drinks and pretzels. Each drink costs $5.50 and each pretzel costs $3.25. She bought 3 more drinks than pretzels. Determine the number of drinks and the number of pretzels that Serenity bought.

Answer 1

10 drinks

7 pretzels

Explanation:

Let number of drinks be "d" and number of pretzels be "p"

Total of 77.75 with drinks costing 5.50 and pretzels 3.25 each. Thus we can write:

5.50d + 3.25p = 77.75

3 more drinks than pretzels, that would be:

d - 3 = p

Now replacing 2nd equation in 1st, we get and equation in d and solve for d first:

`5.50d + 3.25p = 77.75\\5.50d + 3.25(d-3) = 77.75\\5.50d+3.25d-9.75=77.75\\8.75d=87.5\\d=10`

So she bought 10 drinks.

We know p = d - 3, so p = 10 - 3 = 7

So she bought 7 pretzels