The factor of safety using modified Goodman criterion is

Question

In a structural member under fatigue loading, the minimum and maximum stress developed at the critical point are 50 MPa and 150 MPa, respectively. The endurance, yield, and the ultimate strengths of the material are 200 MPa, 300 MPa, and 400 MPa, respectively. The factor of safety using modified Goodman criterion is 

      (a) $\frac{3}{2}$                                                                   (b) $\frac{8}{5}$ 

      (c) $\frac{12}{7}$                                                                  (d) 2