Can someone please check my work? And also why would someone use the pulley arrangements of apparatus B, C, and D

Apparatus A - The pulley is tied to the support Force needed to lift the mass without the pulley = TON Force needed to lift the mass with the pulley =_ 4. 9 N What is the mechanical advantage? 1.9N ma= 9.9N Why would anyone use this pulley arrangement? to change direction - we are pulling down and the mass is moving up Apparatus B - The pulley is tied to the weight being lifted mass lifted weight lifted height lifted force required distance pulled m Fg h F d (kg) (N) (m) (N) (m) 0 .5 kg 4. 9 N 0. I m 2.3 N 0. 2) m work done by the pulley (work out) work done by you (work in) W. = Fd = 4. 9 N x 0. 1 m = 0. 49 J W; = Fd = 2.3 N x 0 . 21 m= 0.483J efficiency mechanical advantage E = 100 %% 0. 497 w; 0. 4835 X1007. Fo 4.9 N = 101 %. Fi 2. 13 2.3 N purpose of this pulley setup has a big mechanical advantage Apparatus C - 2 single pulleys Force needed to lift the mass without the pulley = 4 9 / Force needed to lift the mass with the pulley = _RCN What is the mechanical advantage? 4. 9 N = 1. 88 2, 6 N Why would anyone use this pulley arrangement? Apparatus D - 2 double pulleys Force needed to lift the mass without the pulley = _ . 9 N Force needed to lift the mass with the pulley = _ What is the mechanical advantage? 4. 9 N IN -= 4.9 Why would anyone use this pulley arrangement