जब किसी संख्या का 20% भाग 108 में से घटाया जाता है, तो परिणाम वही संख्या प्राप्त होती है। वह संख्या ज्ञात कीजिए।

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?