For the following questions answer them individually
A fruit seller buys some oranges at the rate of 5 for Rs. 10 and an equal number more at 10 for Rs.20. He sells the whole lot at 15 for Rs. 30. What is his loss or gain per cent ?
15 litres of a mixture contains alcohol and water in the ratio 1 : 4. If 3 litres of Water is mixed in it, the percentage of alcohol in the new mixturewill be
A man rides at the rate of 18 km/hr, but stops for 6 mins. to change horses at the end of every 7th km. The time that he will take to cover a distance of 90 km is
A man rows down a river 15 km in 3 hrs. with the stream and returns in $$7\frac{1}{2}$$, The rate at which he rows in still water is
There is 100% increase to an amount in 8 years, at simple interest. Find the compound interest of Rs. 8000 after 2 years at the same rate of interest.
If the number p is 5 more than q and the sum of squares of p and q is 55, then the product of p and q is
If a + b + c = 2s, then $$\frac{(s-a)^{2}+(s-b)^{2}+(s-c)^{2}+s^{2}}{a^{2}+b^{2}+c^{2}}$$ is equal to
If $$a^{3}-b^{3}-c^{3}=0$$ then the value of $$a^{9}-b^{9}-c^{9}-3a^{3} b^{3} c^{3}$$ is
