The next term of an AP  $\sqrt{7}$  , $\sqrt{28}$  , $\sqrt{63}$  ,......is 

The common difference of the AP  $\frac{1}{p}$ , $\frac{1-p}{p}$  , $\frac{1-2p}{p}$  ........is

The sum of first 20 odd natural numbers is

The sum of first 'n' terms of an AP is (3n² + 6n). The common difference of the AP is ______

What is the formula for the  $n^{th}$  term of the AP   $\frac{2}{3},\ 1,\ \frac{4}{3},\ ...$  

If 7 times the 7^th term of an AP is equal to 11 times its 11^th term, then its 18^th term will be