The sum of the squares of two positive numbers a and b (where a > b) is 7 times their product. Find the difference between their squares.
\(\sqrt{15}\,ab\)
\(5\sqrt{3}\,ab\)
\(3\sqrt{5}\,ab\)
\(3\sqrt{5ab}\)
The selling price of 34 books is equal to the cost price of 17 books. Find the loss or gain percentage.
50% loss
\( \frac{100}{17} \) % gain
50% gain
\( \frac{100}{17} \) % loss