19 Two c ars A and B start simultaneously fro m two points P and Q with c ertain speeds
towar ds eac h other. After reaching a point R, speed of A dec reases by 1/3. It then
meets B at a po int S where SQ = 2PR. If he speed of A had beco me 1/3 less at the mid
point of RS the c ars would hav e met at T w here ST = PR/4. Find RS: PR.
(a) 5: 1 (b) 6: 1 (c) 8:1 (d) 10:1

• condition (1)
  
  (PR/Sa)+(3SR/2Sa)=2PR/Sb-------(1)
  
  condition (2)
  
  (PR+RS/2)/Sa+3/2Sa=QT/Sb
  
  (8PR+4RS+6RS+3PR)/8Sa=QT/Sb=2PR/Sb-----(2)
  
  dividing (1) by (2)
  
  (11PR+10RS)/(4PR+6RS)=QT/PR
  
  ON SIMPLIFICATION,(put,PQ=PR+RS+ST+TQ)
  
  (11PR+10RS)/(4PR+6RS)=7/4
  
  SOLVING FURTHER,
  
  RS/PR=8:1
  
  so,option (C)
• 12 years agoHelpfull: Yes(3) No(2)
• can u pls explain how do u form the equations ?
• 12 years agoHelpfull: Yes(0) No(0)