For any two real numbers a and b.

a-b2+b-a2 is

A machine depreciates in value each year at the rate of 10% of its previous value. However, every second year there is some maintenance work so that in that particular year, depreciation is only 5% of its previous value. If at the end of the fourth year, the value of the machine stands at Rs 1,46,205, then find the value of machine at the start of the first year.

4 years ago, the respective ratio between 1/2 of A’s age at that time and four times of B’s age at that time was 5 : 12. Eight years hence 1/2 of A’s age at that time will be less than B’s age at that time by 2 years. What is B’s present age ?

There were 42 students in a hostel. Due to the admission of 13 new students, the expenses of the mess increase by Rs. 30 per day while the average expenditure per head diminished by Rs. 3. What was the original expenditure of the mess ?

There are five boxes in a cargo hold. The weight of the first box is 200 kg and the weight of the second box is 20% higher than the weight of the third box, whose weight is 25% higher than the first box’s weight. The fourth box at 350 kg is 30% lighter than the fifth box. Find the difference in the average weight of the four heaviest boxes and the four lightest boxes.

24 men can complete a piece of work in 18 days while 12 women can complete the same piece of work in 28 days. 27 men start working and are replaced by 14 women after 8 days. In how many days will 14 women finish the remaining work?

From a container of milk, 5 litres of milk is replaced with 5 litres of water. This process is repeated again. Thus in two attempts the ratio of milk and water became 81 : 19. The initial amount of milk in the container was

A bottle is full of dettol. One-third of it is taken out and then an equal amount of water is poured into the bottle to fill it. This operation is done four times. Find the final ratio of dettol and water in the bottle.

The Simple interest accrued on an amount of Rs. 2,500 at the end of six years is Rs.1875. What would be the simple interest accrued on an amount of Rs. 6875 at the same rate and Same period?