[Solved] 1. Trigononmetry, Geometry, Cirrus, Calculus 2. Comic book, Atlas, Novel, Brain teasers book 3. Otter, Shark, Dolphin, Sea Lion 4. Pen, Pencil, Eraser, Chalk 5. Golden Delicious, Bartlett, Granny Smith, Jonathon

This riddle has been around for some time on internet platforms such as Instagram, Facebook, and WhatsApp, and many people still argue over what the answer might be, as there are many possibilities. The correct answer is 1. Cirrus because the others are all mathematics 2. Atlas because the others are all for leisure/pleasure reading 3. Shark because the others are all marine mammals 4. Chalk because the others are all desk tools 5. Bartlett because the others are types of apples