A race course is 400m long. A and B run a race and A wins by 5m. B and C run over the same course and B win by 4m. C and D run over it and D wins by 16m. If A and D run over it, then who would win and by how much?

1) A, 8.4m
2) D, 8.4m
3) D, 7.2m
4) A, 7.2m

• 3) D, 7.2m
  
  when A covers 400m
  B covers 395 m
  c covers 391mtrs
  and D covers 407.29 mtrs
• 11 years agoHelpfull: Yes(22) No(20)
• A--400
  B--395
  c--391
  I hope so far its clear
  D 400 then C is 384
  when C=391 D=?
  ?=400*391/384==407.29
• 11 years agoHelpfull: Yes(9) No(3)
• from given data, we can assume that,
  A-B=5 ; B-C=4 ; D-C=16 ;
  substitute B=A-5 from eqn 1 in eqn 2, we get
  A-5-C=4 => C=A-9;
  now subs 'C' value in eqn 3, we get
  D-(A-9)=16
  => D-A=7 (this means if D runs 400m then A runs 393m)
  Therefore, D wins by 7m
• 11 years agoHelpfull: Yes(8) No(0)