How do i solve problems like this? you

The actual width ( w) of a regulation soccer field is 90 meters (m), and the actual length is 120 meters (m). a coach has drawn a scale model of the field on a blackboard. if the longest side of his drawing is 18 cm, how long is the other side of the drawing( w)?

An animal shelter has 21 puppies. if the puppies are 28% of the total dogs and cat population how many dogs and cats are in the animal shelter

The volume of a sphere is increased by 6%. calculate the corresponding percentage increased in it area.