For the following questions answer them individually
Ramana’s salary is decreased by 10%. By what percent his decreased salary be raised to have the original salary?
A sum doubles in 20 years at SI. How long will it take to become 8 times the original amount?
The sum of two numbers is 100 and their difference is 50. The ratio of these numbers is:
The population of a town increases at 10% per annum. If the present population is 160000, what will be the population after 4 years?
The ratio of the volumes of two cubes is 1 : 27. The ratio of other surface areas will be
