Here’s a breakdown of the logic:
To form the word for "ceiling tile," you combine the part for ceiling ("pixn") from "pixngorbl" and the part for tile ("arth") from "arthtusl."
Therefore, the word for "ceiling tile" is "pixnarth."

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?