What value should come in place of the question mark (?) in the following question?

52x14+145018=1998÷?

In a triangle PQR, the side QR is extended to S. ∠QPR = 72° and ∠PRS = 110°, then the value of ∠PQR is

The centroid of a triangle is the point where

If 2pp2-2p+1 = 14, then the value of (p + 1/p) will be

If sin8 θ + cos8 θ – 1 = 0, then what is the value of cos2 θ sin2 θ (If θ ≠ 0 or π/2)?

What is the simplified value of [(sec3x – tan3x)/(sec x – tan x)] – 2 tan2x – sec x tan x?

What is the simplified value of tan (θ/2) + cot (θ/2)?

Two smaller circles touch a large circle internally and pass through the center O of the larger circle. If the diameter of the bigger circle is 28 cm, thenwhat is the area of the bigger circle which is not enclosed by the two smaller circles (in sq.cm)?

If medians of a triangle have lengths 18 cm, 24 cm and 30 cm, then what is the area (in sq.cm) of the triangle?