Need help with this one, would be appreciated if you could tell me how to solve this question.
Dahlia walks from her house to school at 2km/h. After school she jogs back home at 6km/h and saves 15mins. how far does Dahlia live from school?
Thanks!
Need help with this one, would be appreciated if you could tell me how to solve this question.
Dahlia walks from her house to school at 2km/h. After school she jogs back home at 6km/h and saves 15mins. how far does Dahlia live from school?
Thanks!
Let t be the time it takes Dahlia to walk to school at 2 km/h in hours, x the distance she lives from school in km.
speed= distance divided by time so $\displaystyle \frac{x}{t}= 2$. that is equivalent to x= 2t.Dahlia walks from her house to school at 2km/h.
So $\displaystyle \frac{x}{t- 1/4}= 6$. That is equivalent to x= 6(t- 1/4). Together with x= 2t, x= 2t= 6t(t- 1/4). Solve that for t then use x= 2t to find x.After school she jogs back home at 6km/h and saves 15mins. how far does Dahlia live from school?
Thanks!
Hello, xXplosionZz!
Dahlia walks from her house to school at 2km/h.
After school she jogs back home at 6km/h and saves 15mins.
How far does Dahlia live from school?
Recall the formula: .$\displaystyle \text{Distance} \:=\:\text{Speed} \times \text{Time}$
. . We have: .$\displaystyle D \:=\:S\cdot T \quad\Rightarrow\quad T \:=\:\frac{D}{S}$
Let $\displaystyle x$ = distance to school (in kilometers).
She walks $\displaystyle x$ km at 2 km/h.. This takes: $\displaystyle \tfrac{x}{2}$ hours.
She jogs $\displaystyle x$ km at 6 km/h.. This takes: $\displaystyle \tfrac{x}{6}$ hours.
Her jogging time is a $\displaystyle \tfrac{1}{4}$-hour less than her walking time.
Our equation is: .$\displaystyle \frac{x}{6} \;=\;\frac{x}{2} - \frac{1}{4}$
Go for it!