SOLUTION: Luis can drive 3 times as fast as Carlos can ride his bicycle. If it takes Carlos 2 hours longer than Luis to travel 15 miles, how fast can Carlos ride his bicycle?
Question 1028427: Luis can drive 3 times as fast as Carlos can ride his bicycle. If it takes Carlos 2 hours longer than Luis to travel 15 miles, how fast can Carlos ride his bicycle? Found 2 solutions by LinnW, MathTherapy:Answer by LinnW(1048) (Show Source): You can put this solution on YOUR website! Let L = Luis's speed
C = Carlos's speed
L = 3C
Set T = time for Luis to travel 15 miles
C ( T + 2 ) = 15
**
L ( T ) = 15
3C(T) = 15
T = 15/(3C)
**
C ( T + 2 ) = 15
CT + 2C = 15
CT = 15 -2C
T = (15-2C)/C
**
15/(3C) = (15-2C)/C
Multiply each side by C
15/3 = 15-2C
5 = 15-2C
add -10 to each side
-10 = -2C
divide each side by -2
5 = C , C = 5 miles per hour
Checking
Since T = 15/(3C) , T = 15/(3*5) , T = 1 hour for Luis
T + 2 = 1 + 2 = 3 hours for Carlos
L = 3C Luis speed is 3 times as fast
L = 3*5 = 15 miles per hour
Let Carlos’ speed be S
Then Luis’ speed = 3S
We then get the following TIME equation:
45 = 15 + 6S ------- Multiplying by LCD, 3S
45 – 15 = 6S
30 = 6S
S, or Carlos’ speed = , or