# word problem involving functions?

• June 28th 2010, 12:04 AM
greytea
word problem involving functions?
Harpreet travelled 112 km in the same time it took liam to travel 80 km. If harpreet's car travelled 18km/h faster that liam's, what was liam's speed?

Can anyone help me out? I'm terrible with word problems.
• June 28th 2010, 12:09 AM
Prove It
You need to remember that

$D = TV$.

Liam: $80 = TV$ which means $T = \frac{80}{V}$.

Harpreet: $112 = T(V + 18)$

$112 = \frac{80}{V}(V + 18)$

$112 = 80 + \frac{1440}{V}$.

Solve for $V$.
• June 28th 2010, 12:15 AM
greytea
thanks a bunch :)