2 men at same tym start walking towards each other from A n B 72 kms apart. sp of A is 4kmph.Sp of B is 2 kmph in 1st hr,2.5 in 2nd, 3 in rd. n so on…when will they meet

i in 7 hrs ii at 35 kms from A iii in 10 hrs iv midway

• Both are in the opposite direction .... so relative speeds =s1+s2;
  we know that in first hour A move 4km and B move 2 km=4+2=6km in one hour;
  second hour A's speed is constant but B's speed increases by 0.5km that is 2.5=4+2.5=6.5km;
  similarly for every one hour the speeds are in Arithematic progression--->6+6.5+7+7.5+8+8.5+9+9.5+10=72km so it takes 9hours to meet....simply add their distances in every hour by keeping A's speed as constant and increase B's speed 0.5km for every hour...
• 7 years agoHelpfull: Yes(52) No(5)
• Ans:-- ( iv ) midway
  After 9 hours,
  A would have travelled 4*9 = 36 km
  B would have travelled 2+2.5+3+3.5+4+4.5+5+5.5+6 = 36 km
  So, total = 36+36 = 72 km
  So, answer = 9 hours / midway
• 7 years agoHelpfull: Yes(24) No(6)
• 36 km from A.
  bcoz,in first hour speed of a+b is 4+2=6.
  in next hour speed is 4+2.5=6.5.
  and so on ..
  after 9 hours it will become 72 km.
• 7 years agoHelpfull: Yes(6) No(3)
• They meet at midway.because A and B travel 36 kms in same time i.e in 9hrs
• 7 years agoHelpfull: Yes(2) No(1)
• mid way
  at each hour they will travel 6+6.5+7....10
  sole from here
• 7 years agoHelpfull: Yes(1) No(0)
• sum of speed is in ap so n/2[2a+(n-1)*0,.5]=72
  and hence we get n=9
  and now putting the value of n as time we get a travels 36 km
  and b travels 36 km and hence the answer is midway
• 7 years agoHelpfull: Yes(1) No(0)
• Mr.srikanth plz put ur answer explanatory where i m getting a wrong answer here
• 7 years agoHelpfull: Yes(0) No(1)
• midway 9 hrs
• 7 years agoHelpfull: Yes(0) No(0)
• midway
  After 9 hours,
  A would have travelled 4*9 = 36 km
  B would have travelled 2+2.5+3+3.5+4+4.5+5+5.5+6 = 36 km
  So, total = 36+36 = 72 km
  So, answer = 9 hours / midway
• 6 years agoHelpfull: Yes(0) No(0)
• 36 kms covered both by A and B in 9th hrs so they meet midway
• 6 years agoHelpfull: Yes(0) No(0)
• midway.
  72/2 = 36kms.....the distance midway
  A to cover 36 takes 9hrs (9*4)
  B in 9 hrs cover 36 also (2+2.5+3+3.5+4+4.5+5+5.5+6 = 36)
  hence d) midway
• 6 years agoHelpfull: Yes(0) No(0)
• distance travelled by A in "x" hrs =4x
  distance travelled by B in "x" hrs =x/2(2+x/2)
  and x/2(2+x/2)=72-4x
  x=9,-32
  so distance =36 km by A and B
  so they meet midway
• 6 years agoHelpfull: Yes(0) No(0)
• Answer : midway
  Let's divide the distance by two ...
  72/2 = 36kms.....the distance midway
  A to cover 36 takes 9hrs (9*4)
  B in 9 hrs cover 36 also (2+2.5+....+6 = 36)
  hence answer is Midway
• 4 years agoHelpfull: Yes(0) No(1)