1) Algebra homework 2) Complications 3) Difficulties 4) Difficulties to be resolved 5) Flies in the ointment 6) Hitches 7) Math homework 8) Predicaments 9) Puzzles; enigmas 10) Snags 11) Technical hitches 12) Teething troubles 13) Things to be solved 14) What everybody has 15) Work by Aristotle 16) Worries 1) Egos 2) Evils 3) Headaches 4) Ills 5) Issues 
[Aristotle] The Problems (Προβλήματα; Problemata) is an Aristotelian or possibly pseudo-Aristotelian collection of problems written in a question and answer format as its authenticity has been under questioning. The collection, gradually assembled by the peripatetic school, reached its final form anywhere between the third century...
There are various problems that have evolved that are popularly cited by name.
problems Things that cause difficulties or those things that are hard to deal with.