the answer was 224 km, not 225.



(b) Let the total distance = 2x

(x/21) + (x/24) = 10. (8x+7x)/168 = 10. 15x=168*10 ... x=(168*10)/5 ..x = 112



2x =224. No idea how this is how you do this. simple v=d/t shows that the answer is 225. no idea why they take the v=d/t formula and make it more comlpicated.