Consider $A_1,A_2,A_3,.....A_n$ and$B_1,B_2,B_3,.....B_n$ $\ge20$ are two different Arithmetic progression such that $\frac{A_n}{B_1}=\frac{\sum_{i=1}^{n}2A_i}{\sum_{i=1}^{n}B_i}=\frac{B_n}{A_1}=4$, then find the value of
i) $\frac{A_n}{B_n}$
ii)$\frac{B_{10}-B_8}{A_{12}-A_{11}}$
I am not able to proceed as so many ratios are there.