After 63 litres of petrol was poured into an empty storage tank, it was still 10% empty. How much petrol (in litres)must be poured into the storage tank in order to fill it?

If the price of rice increases by 20% and a person reduces its consumption by 20%, by what percentage will his total expenditure on rice decrease?

The count of a certain breed of bacteria was found to increase at the rate of 4% per hour and then decrease by 2% per hour. Find the bacteria at the end of 2 hours if the count was 2,00,000 initially.

Kiran spends 75% of his income. If he saves ₹90000, then his income (in ₹) is:

If 30% of a number exceeds 20% of it by 24, then the number is:

A person spends 50% of his monthly salary on house rent. If he spends ₹912 on transport and ₹3,799 on groceries every month and saves the remaining ₹131, then find his monthly salary (in ₹).

A bus is moving at a speed of 82 km/hr. If its speed is reduced by 28%, then what will be the new speed of the bus (in km/hr)?