David played 20 minutes of basketball with his friends. If that represents 40% of the time he spent with his friends, how long did he play basketball?

Christina can paint 420 square feet in 105 minutes. which unit rate describes the scenario?

How do i start to solve? would appreciate a walk-thru! a bird sitting 16ft above the ground in an apple tree dislodges an apple. after how many seconds does the apple land on the ground? (assuming that no branches will interfere with it's fall)

Lola says these two expressions have the same value. expression a expression b which explains whether lola is correct?