A man covered a certain distance at some speed. Had he moved 3 kmph faster, he would have taken 40 minutes less. If he had moved 2 kmph slower, he would have taken 40 minutes more. The distance (in km) is:
35
36$\dfrac{2}{3}$
37$\dfrac{2}{3}$
40
Explanation:
Let distance = x km and usual rate = y kmph.
Then,$\dfrac{x}{y}-\dfrac{x}{y+3}=\dfrac{40}{60} \Rightarrow$ 2y(y + 3) = 9x ....(i)
And, $\dfrac{x}{y-2}-\dfrac{x}{y}=\dfrac{40}{60} \Rightarrow$ y(y - 2) = 3x ....(ii)
On dividing (i) by (ii), we get: x = 40.
Let distance = x km and usual rate = y kmph.
Then,$\dfrac{x}{y}-\dfrac{x}{y+3}=\dfrac{40}{60} \Rightarrow$ 2y(y + 3) = 9x ....(i)
And, $\dfrac{x}{y-2}-\dfrac{x}{y}=\dfrac{40}{60} \Rightarrow$ y(y - 2) = 3x ....(ii)
On dividing (i) by (ii), we get: x = 40.