A cyclist rides 35km at 10km/h and a further 30km at 12km/h. Find his average speed for the whole journey. ( with steps please )...
2007-06-19 14:50:25 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
duhhh...I already told you the answer...then why did you ever post this question ??????
2007-06-19 20:55:35 · answer #1 · answered by Prithika 2 · 1⤊ 2⤋
To get his average speed, you need total distance and total time. So, the first thing you'll have to do is compute the time for each portion.
Using the formula: distance = rate * time...
35km = 10km/hr * t
(35 / 10) hr = t
3.5 hr = t
30km = 12km/hr * t
(30 / 12) hr = t
2.5 hr = t
Now you know that he took 3.5 hours to do the first leg, and 2.5 hours to do the second.
Use the same equation, this time with total distance and total time, to solve for the average rate:
d = r * t
(35km + 30km) = r * (3.5hr + 2.5hr)
65km = r * 6hr
r = 65km/6hr = 10.833 km/hr
2007-06-19 21:53:57 · answer #2 · answered by McFate 7 · 2⤊ 1⤋