Có 5 bạn A;B;C;D;E .Hỏi có bao nhiêu cách xếp 5 bạn vào một ghế dài gồm 5 chỗ ngồi sao cho : a) 5 bạn ngồi bất kì
b) C ngồi ở giữa.
c) Hai bạn A;E ngồi ở hai đầu bàn.

Two consecutive negative integers have a product of 30. what are the integers?

Which option identifies how kevin should proceed in the following scenario? four years ago kevin designed an mp3 player for young children. now that technology has changed, he would like to update his design to ensure that it encompasses cutting-edge techniques. by creating a third-angle projection of his ideas by designing an isometric projection of his new ideas by referring to past designs and illustrations of his original model by conferring with engineers who have improved upon similar devices

Renee hiked for 6 3/4 miles. after resting, renee hiked back along the same route for 5 1/4 miles. how many more miles does renee need to hike to return to the place where she started? represent your answer as a simplified mixed number, if necessary.