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The fourth grade first volume math homework page 28 answer.
2. A bus and a truck leave from Party A and Party B at the same time. The speed of a truck is four-fifths that of a bus. After a quarter of the journey, the truck and the bus met for 28 kilometers. How many kilometers is it between A and B?

Solution: The speed ratio of passenger cars and trucks is 5: 4.

Then the distance ratio when meeting is 5: 4.

When they met, it was 4/9 of the whole truck journey.

At this time, the truck has traveled all the way 1/4.

4/9- 1/4=7/36 from the meeting point.

Then the whole journey = 28/(7/36) = 144km.

3. Party A and Party B walk around the city, with Party A walking 8 kilometers per hour and Party B walking 6 kilometers per hour. Now both of them start from the same place at the same time. After B meets A, it will take another 4 hours to return to the original starting point. B How long does it take to go around the city?

Solution: The speed ratio of A and B = 8: 6 = 4: 3.

When they met, B walked 3/7 of the way.

Then 4 hours is 4/7 of the whole trip.

Therefore, the time spent on line B in a week =4/(4/7)=7 hours.

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