fb3.png"
                                       alt="A"/> interacts continously with <img class="math"
                                                                                 src="../_images/math/4bc3e94a67870b41b7c20179693e889251e2c136.png"
                                                                                 alt="B"/> for 30 minutes starting at
                        the 10th minute while <img class="math"
                                                   src="../_images/math/4db5b6e