दृष्टिबाधित छात्रों द्वारा मैन्युअल रूप से जोड़, घटाव और गुणा करने के लिए आमतौर पर किस गणितीय गणना उपकरण का उपयोग किया जाता है?

The 'Drain of Wealth' theory was propounded by which Indian nationalist leader?

Which event is considered the turning point in Mahatma Gandhi's leadership in the Indian independence movement?

Which African leader is known for his non-violent opposition to colonial rule?