If the mid-point of the line segment joining the points (a, 4) and (2, 2b) is ( 2,6 ), then the value of ( a + b ) is given by:

If the mid-point of the line segment joining the points (a, $\displaystyle 4$) and ($\displaystyle 2$, 2b) is $\displaystyle ( 2,6 )$, then the value of ( $\displaystyle \mathrm{a}+\mathrm{b}$ ) is given by :