Chan drove for X miles at 45 miles an hour, Y miles at 60 miles an hour, and Z miles at 55 miles an hour. Which expression can be used to find the total numbers of hours that Chan drove?

A. (45+60+55)(XYZ)
B. 45X + 60Y + 55Z
C. (45+60+55)/XYZ
D. X/45 + Y/60 + Z/55

Which answer do you think is right?

Hint: only two operations are involved here -- addition and multiplication.

isn't it B?

You're right. :-)

thanks :)

You're welcome.

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To find the total number of hours that Chan drove, we need to calculate the time taken for each segment of the trip and then add them up.

The time taken for the first segment of the trip is X miles divided by the speed of 45 miles per hour, which gives us X/45 hours.

The time taken for the second segment of the trip is Y miles divided by the speed of 60 miles per hour, which gives us Y/60 hours.

The time taken for the third segment of the trip is Z miles divided by the speed of 55 miles per hour, which gives us Z/55 hours.

To find the total time Chan drove, we add these three times together: X/45 + Y/60 + Z/55.

Therefore, the expression that can be used to find the total number of hours that Chan drove is D. X/45 + Y/60 + Z/55.