Step 1: The correct preposition with “introduced” when referring to a person is “to.”
Step 2: “Introduced with” refers to introducing two people together, not one person to another.
Step 3: “Introduced at” is not a common phrase when referring to meeting a person for the first time.
Thus, the correct answer is: “introduced to.”
Arun’s present age in years is 40% of Barun’s. In another few years, Arun’s age will be half of Barun’s. By what percentage will Barun’s age increase during this period?