Find the differences between the greatest values in the following `: ^(15)C_r and ^(11)C_r`

Find the differences between the greatest values in the following: ^(13)C_r and ^(8)C_r

Find the differences between the greatest values in the following: ^(14)C_r - ^(12)C_r

Find the difference between the maximum value of ^8C_r and ^11C_r

The potential difference V_C-V_D between the points D and C in the following diagram is

Find x if ^(n)P_r = x ^(n)C_r

A circuit consists of two cells, each of e.m.f. E and internal resistances r_(1) and r_(2) are connected in series through an external resistance X. If the potential difference between the ends of the first cell is zero, the value of X in terms of r_(1) and r_(2) will be