If '+' means 'minus', '-' means 'multiplication', '÷' means 'plus' and '×'…

To solve this problem, we must first substitute the given operators according to the instructions and then follow the order of operations, commonly known as BODMAS (Brackets, Orders, Division, Multiplication, Addition, Subtraction).

Step-by-Step Analysis
Define the Operator Substitutions:

'+' means '-'

'-' means '×'

'÷' means '+'

'×' means '÷'

Substitute the Operators in the Expression:

Original Expression: 15 - 3 + 10 × 5 ÷ 5

Substituting the symbols: 15 × 3 - 10 ÷ 5 + 5

Apply BODMAS Rules:

Division first: 10 ÷ 5 = 2.

The expression now looks like: 15 × 3 - 2 + 5.

Multiplication next: 15 × 3 = 45.

The expression now looks like: 45 - 2 + 5.

Addition and Subtraction (left to right): 45 - 2 = 43, and 43 + 5 = 48.

Correct Option
Option A: 48