The annual payment of Rs.1000 in  5 years at 4% per annum simple interest will discharge a debt of

If pq+qr+rp=0 then find the value of $$ {p^{2}\over {p^{2}-qr}}+{q^{2}\over {q^{2}-rp}}+{r^{2}\over {r^{2}-pq}}$$

In the following figure if OA=10 and AC=16, then OB must be:

The measure of each of two opposite angles of a rhombus is 60° and the measure of one of its sides is 10 cm. The length of its smaller diagonal is: 

A trader bought 10 kg of apples for Rs. 405 out of which 1 kg of apples were found to be rotten. If he wishes to make a profit of 10 % at what rate should he sell the remaining apples per kg? 

A man buys a machine for Rs.5,000. After one year, he sells it for Rs.6000. After two years, again he buys the same machine at Rs.8,000 and sells it for Rs.10,000. Find his overall profit percentage for both the transactions.