A man sold an article for ₹ 396 and gained 10% on it. Find the cost price of the article.

The sum of two numbers is 4500. If 10% of one number is 12.5% of the other, find the numbers.

The ages of A and B are in the ratio 7 : 5. Ten years hence, the ratio of their ages will be 9 : 7. Find their present ages.

Find the number whose double is 45 greater than its half.