A Woman travelling at 130% of her usual speed reaches her office 12 minutes early. Her usual time to cover the journey is:
Let's assume the distance of her office is 'd' km.
Let's assume the usual speed of a woman is 'sp' km/h.
$$Usual\ time=\frac{d}{sp}$$Â Â Eq.(i)
A Woman travelling at 130% of her usual speed reaches her office 12 minutes early.
$$Usual\ time\ -\ \frac{12}{60}=\frac{d}{130\%\ of\ sp}$$
$$Usual\ time\ -\ \frac{12}{60}=\frac{d}{1.3sp}$$Â Â Â Eq.(ii)
Put Eq.(ii) in Eq.(i).
$$\frac{d}{sp} -\ \frac{12}{60}=\frac{d}{1.3sp}$$
$$\frac{d}{sp} -\frac{d}{1.3sp} =Â \frac{12}{60}$$
$$\frac{1.3d}{1.3sp} -\frac{d}{1.3sp} = \frac{1}{5}$$
$$\frac{0.3d}{1.3sp} = \frac{1}{5}$$
$$\frac{3d}{13sp}=\frac{1}{5}$$
$$\frac{d}{sp}=\frac{13}{5\times3}$$
$$\frac{d}{sp}=\frac{13}{15}$$
From Eq.(i), Her usual time to cover the journey = $$\frac{13}{15}$$ hours
=Â 0.87Â hours
Create a FREE account and get: