suppose we want to choose 2 letters without replacement, from the 4 letters A, B,C, and D (a) how many ways can this be done, if the order of the choices matters? (b) how many ways can this be done if the order of the choices does not matter?

its a just trust  me

Step-by-step explanation:

a. turk and mcalister

b. howard, mission, and market

c. yes. since streets end some do not cross yet are not parallel to others. example: mcalister and 5th

step-by-step explanation:

parallel lines are lines which do not intersect ever and look a lot like railroad tracks. turk, mcalister and golden gate are examples of these.

intersect are streets which cross each other and a car on one can reach the other. howard, mission, and market intersect with 6th.

skew lines are lines which neither intersect nor are parallel. these lines exist here because some streets end and never intersect another like mcalister and 5th.