On Sunday, Mr. Azom drove to his office from home at speed of 40 km/hr and reached has office 10 minutes late. The next day he increased his speed by 5km/hr Still he was 5 minutes late. The distance from his home to office is
ক20 km
খ15 km
গ26 km
30 kmসঠিক উত্তর
সঠিক উত্তর: 30 km
সঠিক সময়ে পৌঁছানোর সময় t ঘণ্টা ধরলে 40d=t+6010 এবং 45d=t+605। বিয়োগ করলে 40d−45d=605=121, অর্থাৎ d⋅18005=121। তাই 360d=121, ফলে d=30 কিমি।