Final answer:
Bulbul thinks of a 3-digit number, decreases it by 50 and then increases it by 35. We can represent the original number as 'abc', where a, b, and c represent the hundreds, tens, and units digits respectively. The resulting number will be (abc - 15).
Step-by-step explanation:
To solve this problem, we need to go step by step. Bulbul thinks of a 3-digit number, which means the number must be between 100 and 999. Let's represent the number as 'abc', where 'a', 'b', and 'c' represent the hundreds, tens, and units digits respectively.
Now, Bulbul decreases this number by 50, so the new number becomes (abc - 50). Finally, Bulbul increases this result by 35, so the resulting number will be ((abc - 50) + 35).
In mathematical terms, the second step can be written as: (abc - 50) + 35 = abc - 50 + 35 = abc - 15.
Therefore, the resulting number is (abc - 15).