There are n students in a school . If r% among the students are 12 years or younger, which of the following expressions represents the number of students who are solder than 12?

125 gallins of a mixture contains 20% water , What amount of additional water should be added such that water...

The sum of squares of two numbers is 80 and the square of difference between the two numbers is 36. Find the p...

A student loses I mark for every wrong answer and scores 2 marks for every correct answer . If he answers all...

There are two stations of length 162 meters and 120 meters respectively . A train takes 15 seconds to pass fir...

A man rows a certain distance along the stream and against the stream in 1 hour and 1.5 hours respectively . I...

A milkman pays tk. 6.40 per liter of milk. He adds water and sells the mixture at tk. 8per liter. By doing thi...