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Re: Julie left home for examination centre at 9:00 am and the reporting ti
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03 May 2023, 08:57
Julie had to reach the examination center at 10:15 am, which means she had 1 hour and 15 minutes to reach there. She left home at 9:00 am and drove for half an hour, which means she had 45 minutes left to reach the examination center.
Let's assume that the distance from Julie's home to the examination center is 'd' km.
During the first half an hour, Julie drove at an average speed of 20 km/hr. Therefore, she covered a distance of 20 x 1/2 = 10 km.
Let's calculate the remaining distance to be covered by Julie to reach the examination center:
Remaining distance = d - 10
Now, Julie increases her speed by 40% and covers the remaining distance in 45 minutes.
The new speed of Julie after the increase of 40% is:
New speed = 20 + (40% of 20) = 28 km/hr
Time taken to cover the remaining distance of (d - 10) km at the new speed of 28 km/hr is 45 minutes or 3/4 hour.
Therefore, using the formula:
time = distance / speed
We get:
3/4 = (d - 10) / 28
Solving this equation, we get:
d - 10 = 21
d = 31 km
Therefore, the distance of the examination center from Julie's home is 31 km. The answer is option (B) 31km.