When is Human Rights Day observed

Given that (3a + 7b = 54) and (ab = 24), determine the value of (9a² + 49b²).

The certain sum amounts to Rs11313.5 in 2(1/2) years at 12% p.a., interest compounded 10 months. The sum (in Rs) is:

Find the number of zeroes in 18 × 125 × 20 × 32.

If (2a + b)/(3b - 2b) = 13/2 then 'b' is what percent of 'a'?

   = ?

If (a + b) = 17 and (a² + b²) = 145, then find the value of (a × b).

If x² + y² + z² = xy + yz + zy (x≠0), then the value of (5x+3y-4z)/2x is

when x =4 and y =-6 then find the value of 27x³ +58x²y +31xy² +8y³?

What will come in the place of question mark (?) in the given expression?

?² = (392 × 224) ÷ (112 × 28) + 6²