1. a) the lifetime of the radioactive decay follows an exponential trend therefore the detection is also exponential with respect to the time difference.
1. b) the angle between 1&2 is 90 deg while the angle between 1&3 is 180 deg. the probability of detection by the detectors and hence the corresponding events/counts is highly dependent on the dipole orientation. since 1&3 are 180 deg they are aligned along the same axis therefore giving higher counts.