Step 1: Identify the number of sides in each shape:
Step 2: By comparing all, RECTANGLE stands out, and its relation to 8 is an outlier.
Conclusion: The odd one out is RECTANGLE - 8 because the number of sides in the figure is more directly related to the second number in the other options.

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?