Suppose we want to choose 3 objects, without replacement, from the 4 objects pencil, eraser, desk, and chair.

4 ways of choosing

Step-by-step explanation:

If you want to choose 3 objects, without replacement, from the 4 objects which are distinct, then permutation i.e then their arrangement doesn't really matter. Only their combination will be considered

That means, order of choosing doesn't matter,

pencil/ eraser/ desk will be same as  eraser/ desk/ pencil.

Number of ways of selecting 3 objects out of 4 distinct objects is:

⁴C₃ =

⁴C₃ =

⁴C₃ = 4

So, there are 4 ways of choosing

last option

step-by-step explanation:

given that δdef is right and isoceles,

assuming that side df is the hypotenuse means that de an ef are the other 2 sides that intersect at 90° and are of equal length.

because they are of equal length, we can say that they are congruent

because they intersect at 90°, their slopes must be opposite reciprocals.

only the last option satisfies these conditions.

i need a diagram

step-by-step explanation:

no