A n B ar 90 km apart they start to move each other simuntaneously A at speed 10 n B at 5k/hr if every hour they duoble their speed what is distancethat A pass untill he meet B

• relative distance b/w a and b=90 km
  after 2 hrs a's speed is 20 km/hr and b's speed is 10 km/hr
  relative speed after 2 hrs is 30 km/hr
  relative time=90/30=3 hrs
  so after 3 hrs they will meet each other
  and a covers 20*3=60 kms
  
  
• 10 years agoHelpfull: Yes(17) No(0)
• in 2 hours a covers (10+20)=30 km
  b covers( 5+10)=15 km, total covered=45
  in the next hour they have to cover (90-45) km with the speeds 40km/hr and 20 km/hr respectively
  let them take another t hrs to meet
  so sum of the distance to be covered by both is 45km
  (40*t)+(20*t)=45km
  gives t= (3/4) hrs
  we need to fid out the distance covered by a
  which equals to =30+(40*(3/4))=60 km
  
• 11 years agoHelpfull: Yes(16) No(9)
• speed a speed b
  1st hr 10kmph 5 kmph total distance covered=15*1= 15km
  2nd hour 20 10 =30*1=30km
  3rd hour 40 kmph 20 kmph =60*1=60km but now we need only 45
  so time taken is t=45/60=3/4
  so total time taken =2+3/4 =11/4
  so distance travlled by a is 10+20+(40*3/4)=10+20+30=60
• 11 years agoHelpfull: Yes(10) No(1)
• Speed of A is always double of B's speed.Let A's speed=2x B's speed=x .Every houur both their speeds double.Let them meet after time t.It result in equation
  2xt=xt=90 thus xt=30
  Dist coverd by A= 2xt =2*30=60km
• 10 years agoHelpfull: Yes(4) No(0)
• speed of a and b are in the ratio 1:2
  so to covver the distance of 90 km
  a is (1/3)*90=30
  b is (2/3)*90=60
• 10 years agoHelpfull: Yes(2) No(0)
• from 90 km A will cover 30(10+20) km in first 2 hour and 15(5+10) km by B.
  now remaining distance=90-(30+15)=45
  and at this position speed of A will be 40km and speed of B will be 20km.
  total speed(A+B)=60km
  distance=45km
  so both will take 45 min.
  and in this 45 min a will cover 30km bcoz at this position speed of A is 40km.
  So total distance covered by A will be 30+30=60km
  
• 10 years agoHelpfull: Yes(1) No(0)
• 1st hour A cover distance 10km/h
  2nd hour A cover dis 20km/hr
  3rd hour A cover dis 40km/h
  and now 1st Hour B cover 5km/h
  2nd h B cover 10km/hr
  3rd h B cover 20km/h
  so total dis cover by A 60 at the time of meet becaudse both in running stage
  
• 11 years agoHelpfull: Yes(0) No(2)