Question

An aeroplane flies along the sides of an equilateral triangle with speed of 300 km/hr, 200 km/hr, 240 km/hr. The average speed of the plane while flying around the triangle is:

a. 250 km/hr

Answer 1

Answer:

Average speed = total distance covered\time taken

Let side of equilateral triangle = a km

Total distance covered = (a + a +a)km = 3a km

Time taken = sum of time taken by each side

                  = (a\300+a\300+a\300) hr

                  =  4a + 6a + 5a\1200 hr

                  =  15a\1200 hr

                  = a\80 hr

Hence, average speed = 3a\a\80

                                    = 240 km/hr