Sunita traveled 15 km 268 m by bus, 7 km 7 m by car, and 500 m on foot in order to reach her school. How far is her school from her residence?

Hint: Add the distance given in meters separately and distance given in kilometers separately. If the added distance in meters exceeds 1000 then change this 1000 m into 1 km, by using the conversion: 1 km = 1000 m.

Complete step-by-step solution:
We know that the sum of two quantities is possible only when their dimensions or unit are the same.
In the above question, we have to add distances covered by Sunita. We must add the distances given in kilometers together and the distances given in meters together. We cannot add the distance given in meters with the distance given in kilometers directly because their units are not the same.
Now, it is given that Sunita traveled 15 km 268 m by bus, 7 km 7 m by car, and 500 m on foot in order to reach her school. We have to find the total distance between her residence and the school, i.e. the total distance traveled by Sunita. This is because whatever distance she will travel will be the required distance between her residence and the school.
Distance travelled by Sunita in meters = (268 + 7 + 500) = 775.
Now, distance travelled by Sunita in kilometers = (15 + 7) = 22.
Therefore, the total distance traveled by Sunita is 22 km 775 m.
Hence, the distance between her residence and the school is 22 km 775 m.

Note: Always remember that the addition or subtraction of two quantities takes place when their units or dimensions are the same. We can also solve this question by changing the distances given in meters into kilometers directly in the first step only. One may note that if we need to convert the obtained distance into kilometers only then we have to convert 775 m into km by dividing it by 1000.