What is the simplified value of (cosec A – sin A)(sec A – cos A)(tan A + cot A)?

What is the simplified value of sec6 A – tan6 A – 3 sec2 A tan2 A?

ΔPQR has sides PQ and PR measuring 983 and 893 units respectively. How many such triangles are possible with all integral sides?

In the given fig, ST||RP, then what is the value of supplementary angle y (in deg)?

If x – (1/x) = 3, then what is the value of (2x4 + 3x3 + 13x2 – 3x + 2) / (3x4 + 3)?

If x2 + (1/x2) = 31/9 and x > 0, then what is the value of x3 + (1/x3)?

If a = 73, b = 74 and c = 75, then what is the value of a3 + b3 + c3 – 3abc?

A person lent certain sum of money at 10% per annum simple interest. In 20 years the interest amounted to Rs 500 more than the sum lent. What was the sum lent (in Rs)?