What is the average (arithmetic mean) of all multiples of 10 from 10 to 400 inclusive ?

If f(x)=5-2x and f(3k)=f(k+1),then f(k) = ?

In a batch of 500 students, forty percent are girl. Twenty-five percent of the boys and half of the girls agre...

If the product of two numbers is 102 and their sum is 23 then what is the highest number?

Amir spent one-third of his money on buying software and 50% of the remaining money on clothing. Now he has 15...

Find the odd figure of the following :

Masum can do a job in 2 hours. Hashem can do the same job in 3 hours. If they work together , how many hours w...