Can anyone me solve this problem number 24?

If kn = 9 cm, mn = 21 cm, rs = 42 cm, and ps = 18 cm, what is the scale factor of figure klmn to figure pqrs?

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?

Kelli swam upstream for some distance in a hour.she then swam downstream the same river for the same distance in only 6 minutes.if the river flows at 5km/hr, how fast can kelli swim in still water?