25+15:3

Assuming ":" means division and standard order of operations (division before addition):

• 15 ÷ 3 = 5
• 25 + 5 = 30

So, the result is 30.

If the expression was meant as (25 + 15) ÷ 3, the result would be 40 ÷ 3 ≈ 13.33.