`S_1, S_2`, are foci of an ellipse of major axis of length `10 units` and `P` is any point on the ellipse such that perimeter of triangle `PS_1 S_2`, is `15`. Then eccentricity of the ellipse is:

S_1a n dS_2 are the foci of an ellipse of major axis of length 10 units, and P is any point on the ellipse such that the perimeter of triangle P S_1 is 15. Then the eccentricity of the ellipse is 0.5 (b) 0.25 (c) 0.28 (d) 0.75

S and T are the foci of an ellipse and B is the end point of the minor axis. If STB is equilateral triangle, the eccentricity of the ellipse is

P is any point on the ellipse x^2/144+y^2/36=1 and S ans S' are foci, then the perimeter of triangle SPS' is :

S and T are foci of an ellipse and B is an end of the minor axis , if STB is an equilateral triangle , the eccentricity of the ellipse , is

S and T are foci of an ellipse and B is an end of the minor axis , if STB is an equilateral triangle , the eccentricity of the ellipse , is

S and T are foci of an ellipse and B is an end of the minor axis , if STB is an equilateral triangle , the eccentricity of the ellipse , is

S_(1) and S_(2) are the foci of an ellipse and B is the end of the minor axis. If the triangle S_(1) S_(2) B is an equilateral triangle, then eccentricity of the ellipse is