For a sequence $\left(t_n\right)$, if $S_n=5\left(2^n-1\right)$ then $t_n=$ .........

If $A, B, C$ are $p^{\text {th }}, q^{\text {th }}$ and $r^{\text {th }}$ terms of a GP respectively then $A^{q-r} \cdot B^{r-p} \cdot C^{p-q}=\ldots \ldots$

If $\sum_{r=1}^n(2 r+1)=440$, then $n=$ ...............

If the sum of an infinite GP be 9 and sum of first two terms be 5 then their common ratio is ..........