Time taken for Lee to travel 315km = 315/90 = 3.5hrquestionable_i wrote:Can anyone help me with these questions. Thank you.

http://imgur.com/nYsBS2D

But Wong has a 30min head start, so his traveeling time is 4hr instead.

The distance Wong covers in 4hrs = 60X4 = 240km

A) since 240k is 2/3 of journey,

3/3 of the journey = (240/2) X 3 = 360km ###

B) For 360 km,time take for mr wong is = 360/60 = 6hrs

He started at 10am, 6 hours later is 4pm ####

C) Base on Lee's start time (10:30am), which is 30min later. Wong would have closed the distance between them,

Distance WOng travelled in 30min = 60 X0.5 = 30km

Distance between Wong and Lee= 360-30 = 330km

Time take to meet, = 330/(90+60) = 2.2 hrs or 2hr and 12 min. (note, opposing direction we use sum of speed. If they are travelling the same direction we use the difference in speed)

From 10:30am, another 2h and 12 mins later, the time will be = 12:42pm ### That's whn they meet.