A sandwich costs $0.75 more than a container of milk. A customer buys 4 sandwiches and 4 containers of milk. The customer pays $7.00.

What is the cost of a sandwich?

Assume that the cost of the milk is x.

We are given that a sandwich costs 0.75$ more than the cost of milk. This means that:

cost of sandwich = cost of milk + 0.75

cost of sandwich = x + 0.75

Now, the customer bought 4 sandwiches and 4 containers of milk at the cost of 7$.

We will transform this into an equation as follows:

total cost = cost of 4 sandwiches + cost of 4 containers of milk

7 = 4 (x+0.75) + 4 (x)

Solve the above equation to get x as follows:

7 = 4x + 3 + 4x

7-3 = 8x

8x = 4

x = 0.5

Therefore:

cost of milk = x = $0.5

cost of sandwich = x+0.75 = 0.5+0.75 = $1.25