Three massless blocks with masses of $1\mathrm{.}0,2\mathrm{.}0$ and $4\mathrm{.}0$ kilograms are connected by strings, one of which is on the side

frictionless with negligible mass as shown passes over a pulley. Each of the following calculate one

a$.$ Acceleration of a $4$ kilogram block

b$.$ Tension in the rope supporting the $4-$kilogram block

c$.$ Tension in the rope connected to the $1$ kilogram block