The numbers in the sequence are perfect squares except for 23, which is not a perfect square.
The perfect squares are: 1, 4, 9, 16, 25, 36.
Thus, 23 is the odd one out.
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?