A car travels the first half of a journey at a speed of 80 km/h and the next half of the journey at 100 km/h. What is the average speed of the car? [Give your answer correct to 2 places of decimal.]
Answer & explanation
Correct answer: option 2
Average speed = \(\frac{ 2 × S1 × S2 }{S1 + S2 }\)
= \(\frac{ 2 × 80 ×100 }{80 + 100 }\)
= \(\frac{ 16000 }{180 }\)
= 88 .89 km/h ( approx)