If the sum of two numbers is 15 and one of the numbers is 7, what is the other number?

To determine the other number, you start from the information given: the sum of two numbers is 15 and one of the numbers is 7.

To find the other number, you can set up the equation:

[

\text{First number} + \text{Second number} = 15

]

Substituting the known value into the equation, it looks like this:

[

7 + \text{Second number} = 15

]

To isolate the "Second number," you subtract 7 from both sides of the equation:

[

\text{Second number} = 15 - 7

]

Calculating this gives:

[

\text{Second number} = 8

]

Therefore, the other number is 8. This reasoning confirms that the answer is indeed correct based on the provided information and calculation. The correct option reflects the necessary logic and mathematical operation needed to solve the problem.