First test passed.
- implemented caclulatePrimeNumbersLessthan1000 method
- added isNumberPrime() helper method.
Second test passed.
- Removed logging printlns from calculatePrimeNumbersLessthan1000()
- Implemented findStringsContainingValue()
Third test passed.
- Implemented factorial() method.
All tests pass.
- implemented question method()
- Used HashMap to store answers to questions since complexity for
  insertion and access are so low.