Dahlai walks from home to school at 2km/h. After school she jogs back home at 6km/h and saves 15 mins. How far away is her house from school? I don't even know how to approach this, all help is appreciated.
Hello, xXplosionZz!
Recall the formula: .$\displaystyle d \:=\:rt \quad\Rightarrow\quad t \:=\:\tfrac{d}{r}$
Dahlai walks from home to school at 2km/hr.
After school she jogs back home at 6km/hr and saves 15 mins.
How far away is her house from school?
She walks $\displaystyle x$ km at 2 km/hr.
. . This takes $\displaystyle \frac{x}{2}$ hours.
She jogs $\displaystyle x$ km at 6 km/hr.
. . This takes $\displaystyle \frac{x}{6}$ hours.
Her jogging time is $\displaystyle \tfrac{1}{4}$ hour less than her walking time.
. . The equation is: .$\displaystyle \frac{x}{6} \:=\:\frac{x}{2} - \frac{1}{4}$
Got it?