What is the eccentricity of the ellipse if the angle between the straight lines joining the foci to an extremity of the minor axis is 90°?

Two dice each numbered from 1 to 6 are thrown together. Let A and B…

Two dice each numbered from 1 to 6 are thrown together. Let A and B…

An urn contains one black ball and one green ball. A second urn contains one…

An urn contains one black ball and one green ball. A second urn contains one…

What is the most probable number of successes in 10 trials with probability of success…