Advanced Algebra 1 with probability! Can somebody help me understand this math? I'm struggling.

Haley buys 9 pounds of apples for $3. how many pounds of apples can she buy for $1?

In right ∆abc shown below, the midpoint of hypotenuse ac is located at d and segment bd is drawn.if ab = 12 and bc = 16, then explain why bd = 10. hint: consider what you know about the diagonals of a rectangle.

Kai walked one and two-thirds of a mile on saturday and four and one-sixth of a mile on sunday. how many miles did kai walk?