The total force is 49.589 N or 50 N. The scientific solution is quite long.... First, find the horizontal and vertical forces of each child. The horizontal force is "Fcos(angle)" while vertical force is "Fsin(angle)". So in first child , its horizontal force is "20cos30°" and the vertical force is "20sin30°". In second child, the horizontal force is "30cos45°" then the vertical force is "30cos45°"......after finding the forces, we add them(according to type) to get the total(€) forces.....€Horizontal Force= 20cos45°+30cos45 =10√3 +15√2………€Vertical Force= 20sin45°+30sin45 =10+15√2…........Now we can find the total force, The equation would be " Total force= √[(€Horizontal force)^2+(€Vertical force)^2]"...=√[(10√3+15√2)^2+(10+15√2)^2]=√[(38.534)^2+(31.213)^2]=√[(1484.869)+(974.251)]=√[2459.12]=49.589 N---answer. Hope you'd understood my explanation :-)