Plz answer. i'm dumb i know

Aball is dropped from a height of 10m above the ground. it bounce to 90% of its previous height on each bounce. what is the approximate height that the ball bounce to the fourth bounce?

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?

Which of the following transformations will make coincide with ? a. counter-clockwise rotation 90º about a, followed by a translation 5 units to the right b. translation 5 units to the right, followed by a reflection across the y-axis c. translation 5 units to the right, followed by a reflection across the x-axis d. translation 1 unit up and 5 units to the right, followed by a reflection across the x-axis