i would highly recommend to go through this link for all speed, dist time....(the organization of data matters a lot in such questions)

distance-speed-time-word-problems-made-easy-87481.html d s t

john 500 x 500/x a--->>-------b

jane 500 y 500/y b------<<---a

question is who reached earlier? (time taken to cover 500kms is greater for whom)

1. after 5 hrs they meet at 200 frm a, for john

that means 300 from b, for jane (since total is 500)

we can find out speeds since the time is same when they meet at point travelling towards each other.

john 200 40 5

jane 300 50 5

BUT here what happens for rest of 300 for john and rest of 200 for jane is not known.

you may take cases

case1) when jane is travelling at 10kmph and john at 70kmph for rest of their distances left i.e 300 and 200 respectively ( since max is 70kmph)

300/10 and 200/70 i.e 30 hrs and 2.8 hrs approx so total time for john = 5+30 =35hrs and jane = 5+2.8= 7.8hrs .

.here jane arrived earliercase 2) when jane is travelling at 70kmph and john at 10kmph for rest of their distances left i.e 300 and 200 respectively ( since max is 70kmph)

300/70 and 200/10 i.e 4.3 hrs approx and 20 hrs so total time for john = 5+4.3 =9.3hrs and jane = 5+20= 25hrs ..

here john arrived earlier NOT SUFFICIENT

2. jane avg speed y=60kmph so time is 500/8 ...8.3 hrs for jane

Nothing is known about john x=??

NOT SUFICIENT

1. and 2. together

we know Jane took 8.3 hrs overall for 500kms i.e his speed y=60kmph

we also know john took 5 hrs for 200 kms ; let john drive at max speed which is 70kmph for remaning 300kms

so john took 300/7 ..approx 4.3hrs ;so total time is 5+4.3 = 9.3 hrs

even travelling at max speed for remaining distance john takes 9.3 hrs which is more than jane (8.3 hrs)

so we can conclude PAtrick jane

reached earlier ( as usual)