Please I need a step by step explanation ASAP thank you​

Will used 20 colored tiles to make a design in art class. 5/20 of his tiles were red. what is an equivalent fraction for the red tiles?

Which is a reasonable estimate of the amount of water in a small, inflatable pool used by children?

If a 36 inch yardstick casts a 21 foot shadow, how tall is a building whose shadow is 168 feet? what is the scale factor