Suppose we want to choose 6 letters, without replacement, from 15 distinct letters. (A) how many ways can this be done, if the order of choices is not taken into consideration? (B) How many ways can this be done, if the order of choices is taken into consideration?

Areflection of shape i across the y-axis, followed by a , and then a translation left 6 units and down 4 units confirms congruence between shape i and shape ii. alternatively, a of shape ii about the origin, followed by a reflection across the y-axis, and then a translation right 4 units and up 6 units confirms congruence between shape ii and shape i.