पुनर्मूल्यांकन के बाद, एक छात्र के अंक 80 से बढ़कर 92 हो गए। अंकों में प्रतिशत वृद्धि कितनी है?

A person saves 90% of his income. If his expenditure is ₹520, find his income (in ₹).

By how much is 30% of 60 greater than 25% of 40?

By how much is 30% of 50 greater than 35% of 30?