It takes two hours for a person X to mow the lawn. Y can mow the same lawn in four hours. How long (in minutes) will it take X and Y, if they work together to mow the lawn?

The missing number in the given sequence 343, 1331, _______, 4913 is

For what values of k given below is $${{{{\left( {k + 2} \right)}^2}} \over {k - 3}}$$ an integer?

The three roots of the equation f(x) = 0 are x = {-2, 0, 3}. What are the three values of x for which f(x -3) = 0?