Evaluate:

$\sqrt{\Big[5 + 2\dfrac{21}{25}\Big] \times \dfrac{0.169}{1.6}}$

Evaluate:

$\sqrt{5\Big[2\dfrac{3}{4} - \dfrac{3}{10}\Big]}$

A man, after a tour, finds that he had spent every day as many rupees as the number of days he had been on tour. How long did his tour last, if he had spent in all ₹1,296?

Out of 745 students, maximum are to be arranged in the school field for a P.T. display, such that the number of rows is equal to the number of columns. Find the number of rows if 16 students were left out after the arrangement.