Jake is faster than Paul. Jake and Paul each walk 40 km. The sum of their speeds is 13 km/h and the sum of time taken by them is 13 hours. Then Jake’s speed in KMPH is equal to
(a)9
(b)7
(c)8
(d)13

• s1+s2=13;
  (40/s1)+(40/s2)=13;
  solving these eqn u get s1=8 or 5.
• 11 years agoHelpfull: Yes(30) No(0)
• speed of jake is x & speed of Paul is 13-x
  time taken by Jake y & time taken by Paul is 13-y
  as we know that speed*time=distance
  so
  xy=40.....(1)
  (13-x)(13-y)=40.....(2)
  now put the value of y in (2)
  (13-x)(13-40/x)=40
  (13-x)(13x-40)=40x
  13x^2-169x+520=0
  now x=8
  
• 11 years agoHelpfull: Yes(9) No(0)
• option c
  J+P=13;
  (40/J)+(40/P)=13;so we get J*P=40;
  Hence the speeds are J=8kmph and P=5kmph(J>P)
• 11 years agoHelpfull: Yes(5) No(3)
• go for trial and error
  as jake is faster than paul
  let us check option c jake= 40/8 = 5
  paul= 40/5 = 8
  5+8 = 13hrs and 8km + 5km = 13km
• 11 years agoHelpfull: Yes(4) No(1)
• speed of jake be x and paul be 13-x
  time" " t " " 13-t
  xt=13-t-x
  t=40/x
  x=8
• 11 years agoHelpfull: Yes(1) No(0)
• C)8
  Sum of speeds =13 ==> s1+s2=13 ....1
  sum of time=13 ==> t1+t3=13 ==> (40/s1)+(40/s2)=13 ....2
  solving 1 and 2 we get
  s1=8,5
  since s1(jake) runs faster than s2(paul)
  ans will be 8kmph
• 11 years agoHelpfull: Yes(1) No(0)
• let jake speed =x km/hr and paul speed= 13-x km/hr
  so 40/x + 40/ 13-x = 13
  40(13-x)+40 x=13(x)(13-x)
  520-40 x+ 40 x= 169x-13x^2
  520+13x^2-169 x=0
  x^2-13x+40=0
  (x-8)(x-5)=0
  x= 8,5
  but jake is faster than paul
  so jake =8km/hr and paul = 5km/hr
• 6 years agoHelpfull: Yes(1) No(0)
• if we take from answer jake is fast so jake speed is greater if we take a 8km/h as a jake speed then we require 5hrs and for paul take speed as 5km/hr bcs
  j+p=13 so we get sum of thire speed as 8+5=13 and hrs 5+8=13 so ans is c
• 11 years agoHelpfull: Yes(0) No(0)
• then jakes speed ==8 km/hr since he is faster !!!
• 11 years agoHelpfull: Yes(0) No(0)
• 40 is divisible of 5 and 8.
  8*5=40
  and the sum of there speeds=8+5=13
  
• 8 years agoHelpfull: Yes(0) No(0)
• 40/x+40/(13-x)=13 -----1
  by solving eq1 we get x as 8 and 5
  jake is faster than poul.so,speed of jake is 8
• 5 years agoHelpfull: Yes(0) No(0)