Anjali travels from her home to office at a speed of 40km/hr and returns from her office by increasing her speed by 50%. What is the average speed for her round journey?Choose the best optionClear Response30 km/hr60 km/hr72 km/hr48 km/hr
Question
Anjali travels from her home to office at a speed of 40km/hr and returns from her office by increasing her speed by 50%. What is the average speed for her round journey?Choose the best optionClear Response30 km/hr60 km/hr72 km/hr48 km/hr
Solution
The average speed is calculated by total distance divided by total time.
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The speed from home to office is 40 km/hr. Let's assume the distance between her home and office is D km. So, the time she takes to reach office is D/40 hours.
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She returns from her office with a speed increased by 50%, which means her return speed is 40 km/hr + (50/100)*40 km/hr = 60 km/hr. So, the time she takes to return home is D/60 hours.
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The total distance for the round trip is 2D (D km to the office and D km return), and the total time is D/40 + D/60 = D*(1/40 + 1/60) = D*(1/24) hours.
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Therefore, the average speed for the round trip is total distance divided by total time, which is 2D / (D/24) = 48 km/hr.
So, the correct answer is 48 km/hr.
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