Which of the following is not covered under an insurance

If (r + s + t) = 12 and (rs + st + tr) = 60, then find the value of (r² + s² + t²).

Find the value of ‘x’ in the given expression:

(49/16)^x × (64/343)^x-1 = 4/7

If x + 1/x = 3, find the value of x³ + 1/x³.

If x² – 10x + 20 = 0, then find the value of (x – 3)² + 1/(x – 3)²

What will come in place of the question mark (?) in the following series?

23, 46, ?, 184, 368, 736

If x⁴ + x³ + x² + x + 1 = 0, then find the value of x¹⁵²⁵ + x⁷²⁰ + 14 + x³²⁰ =?

What is the average of the first 20 multiples of 12?

Length of each side of a rhombus is 13 cm and one of the diagonal is 24 cm. What is the area (in cm²) of the rhombus?