Find the missing area and dimensions (base and height) for the generic rectangle below

Find three consecutive numbers such that the sum of one-fourth the first and one-fifth the second is five less than one-seventh the third

Three coins are flipped. what is the probability that there will be at least two tails?

What is the ratio for the surface areas of the cones shown below, given that they are similar and that the ratio of their radil and altitudes is 4: 3? 23