Sigma n

Q. A pack contains n cards numbered from 1 to n. Two consecutive numbered cards are removed from the pack and the sum of the numbers on the remaining cards is 1224. If the smaller of the numbers on the removed cards is k, then k - 20 is equal to___

Q. Find the sum of n terms of the series $\frac{1}{1+1^2+1^4}+\frac{2}{1+2^2+2^4}+\frac{3}{1+3^2+3^4}+.....$

Q. Solve the given quadratic equation by factorization
$9x^2-3x-2=0$

Q. If $\underset{i-1}{\sum ^n}i=\frac{n(n+1)}{2},then\underset{i-1}{\sum ^n}(3i-2)=$

1. $\frac{n(3n-1)}{2}$
2. $\frac{n(3n+1)}{2}$
3. n(3n + 2)
4. $\frac{n(3n+1)}{4}$

Q. Solve the following equations:
$x^4-10x^2-20x-16=0$.