840, 2520, 630, 3150, ?, 

(408 × 680)÷(20% of 680) = (250 × 260)÷ 10 + ? – 4500

If x + y + z = 7, x² + y² + z² = 85 and x³ + y³ + z³ = 842, then the value of √3 xyz is:

If x = (2+√3)/(2-√3), y = (2-√3)/(2+√3)

Then find out the value of (x²+y²-xy)/(x²+y²+xy)

If x : y : z = 6 : 7 : 11, and (2x + 3z) = 180, then find the value of y.

If 1/(x+ 1/(y+ 1/z)) = 13/30, then find x+y+z= ?

If (a + b) = 9 and ab = 14, find the value of (a² + b²).

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

(p + q) = 8 and (p² + q² - 6) = 28. If p < q, then determine the value of (p/q).