SOLUTION: C takes 3 hours longer than B to walk 40 kilometers. If C doubles his rate he can cover the same distance in one hour less than B. Find the rate of each. Thanks!

Algebra ->  Rate-of-work-word-problems -> SOLUTION: C takes 3 hours longer than B to walk 40 kilometers. If C doubles his rate he can cover the same distance in one hour less than B. Find the rate of each. Thanks!      Log On


   

Question 22959: C takes 3 hours longer than B to walk 40 kilometers. If C doubles his rate he can cover the same distance in one hour less than B. Find the rate of each. Thanks!
Answer by venugopalramana(3286) About Me  (Show Source):
You can put this solution on YOUR website!
LET B TAKE B HRS TO COVER 40 KM ...SO HIS SPEED IS 40/B...KMPH...
C TAKES 3 HRS LONGER ..THAT IS B+3 HRS TO COVER 40 KM ..
SO HIS SPEED IS 40/(B+3) ....
C DOUBLES THE SPEED .SO HIS SPEED NOW 2*40/(B+3)=80/(B+3)...SO HE NEEDS
40/{80/(B+3)}=(B+3)/2 HRS..TO COVER 40 KM
BUT HE TAKES 1 HR LESS THAN B ... THAT IS B-1 HRS.....SO...WE HAVE...
(B+3)/2=B-1
B+3=2(B-1)
B+3=2B-2
2B-B=3+2
B=5....HENCE SPEED OF B IS 40/5=8 KMPH AND
WE HAVE SPEED OF C =40/(5+3)=40/8=5 KMPH.