Find the missing number in the series:
219, 211, 204, 198, ?, 189
1). 189
2). 192
3). 193
4). 196
5. Density of water is maximum at ______.
6. What smallest number should be added to 2957 so that the sum is completely divisible by 17 ?
7. if x=2+$\sqrt{3}$, then the value of $\frac{x^{2}-x+1}{x^{2}+x+1}$ is
8. If the sum of three consecutive numbers is 15, what is the square of the middle number ?