A parabolic curve is used to connect a 4% upgrade with a 2% downgrade as shown in the below figure. The highest point on the summit is at a distance of (measured horizontally from the first tangent point - (FTP)

A deep cut of 7 m has to be made in a clay with unit weight 16 kN/m^{3} and a cohesion of 25 kN/m^{2}. What will be the factor of safety if one has to have a slope angle of 30° ? Stability number is given to be 0.178 (from Taylor's chart) for a depth factor of 3.