Rehana leaves her home early in the morning so that she can reach her office on time. If she walks at the rate of 7 km/hr then she reaches her office 8 minutes late. But, if she walks at a speed of 8 km/hr, then she reaches her office 4 minutes early. What is the distance in km between Rehana’s house and her office?
A 10
B 11.2
C 11.5
D 12
Solution
Correct Answer: Option B
suppose,
distance from office to home=x difference of time=(8+4)=12 minute=1/5 hour here, x/7-x/8=1/5 or,8x-7x/56=1/5 so,x=11.2 so,distance =11.2 km
অ্যাপ/ওয়েবসাইটে রুটিনভিত্তিক নিয়মিত লাইভ পরীক্ষা হচ্ছে।