নিচের অপশন গুলা দেখুন
- 1958
- 1642
- 1972
- None of the above
1 উত্তর
সঠিক উত্তর হচ্ছে: 1642
ব্যাখ্যা:
ব্যাখ্যা:
The invention of the mechanical calculator. Blaise Pascal invented a mechanical calculator with a sophisticated carry mechanism in 1642. After three years of effort and 50 prototypes he introduced his calculator to the public. He built twenty of these machines in the following ten years.