Suppose that Cindy rides her bike two miles in the same time it takes Bobby to ride his bike three miles. If Bobby rides his bike 5 mph faster than Cindy, find the speed of each rider.
If it's not too much trouble, could you show your work, so I can understand it better. Thanks.
2007-07-09 12:32:57 · 6 answers · asked by jaz 5 in Science & Mathematics ➔ Mathematics
let, cindy's speed be x.
bobby's speed be y.
Time taken for 2 miles (cindy) = time taken for 3 miles (bobby).
Time = dist/speed
2/x = 3/(x+5)
2x + 10 = 3x
x = 10 mph
cindy's speed = 10 mph
bobby's speed = x + 5 = 15 mph
2007-07-09 12:36:53 · answer #1 · answered by Anonymous · 2⤊ 0⤋
Let the speed of cindy and bobby be x and y miles per hour respectively
Then 2/x=3/y
or,3x=2y [by cross-multiplication]
or 3x-2y=0....(eqn 1)
again y=x+5
substituting the value of y in eqn 1,we get
3x-2(x+5)=0
or 3x-2x-10=0
orx=10
Therefore y=10+5=15
Hence the speed of cindy is 10 mph and that of Bobby is 15 mph
2007-07-09 19:45:09 · answer #2 · answered by alpha 7 · 1⤊ 0⤋
x= Cindy's speed
x+5 = Bobby's speed
2/x=3/(x+5)
3x = 2x+10
x = 10 = Ciny's speed
x+5 = 15 = Bobby's speed
2007-07-09 19:39:20 · answer #3 · answered by ironduke8159 7 · 1⤊ 0⤋
Just start guessing and then check your answer.
Guess 5Cindy 10Bobby, nope that is
wrong because Bobby10 is twice speed of 5Cindy.
Guess #2: Guess 1Cindy 6Bobby,
now Bobby is 6 times faster than Cindy.
Guess #3: Guess 10Cindy 15Bobby.
This is the right answer because
15milesBobby and 10milesCindy is
the same as 3+3+3+3+3 for Bobby and
2+2+2+2+2 for Cindy.
Yeah!!
The guy who answered before me, set his equation up because he knows that
Cindy time = Bobby time
rate times time = distance so
distance divided by rate is time
divide sign is /
2007-07-09 19:38:10 · answer #4 · answered by winter_new_hampshire 4 · 1⤊ 1⤋
distince = speed * time
let c be the speed of candy.
c + 5 is the speed of Bobby
2 = ct
3 = (c + 5)t
t = 2/c
3 = (c + 5) 2/c
3c = 2(c + 5)
3c = 2c + 10
c = 10mi/hr
speed of bobby is 10 + 5 = 15 mi/hr
2007-07-09 19:40:06 · answer #5 · answered by 7 · 1⤊ 0⤋
1.609344 kilometers is 1 mile. Can you work with that
2007-07-09 19:39:37 · answer #6 · answered by Lil Samz 1 · 0⤊ 0⤋