Question

Sal exercised by stretching and jogging 5 days last week.

He stretches for a total of 25 minutes during the week.
He jogged for an equal number of minutes each of the 5 days.
He exercised for a total of 240 minutes.

Elena also exercised by stretching and jogging 5 days last week.

She stretched for 15 minutes each day.
She jogged for an equal number of minutes each of the 5 days.
She exercised for a total of 300 minutes

Determine the number of minutes Sal jogged each day last week and the number of minutes Elena jogged each day last week.

Answer 1

• Sal: 43 min/day
• Elena: 45 min/day

Explanation:

The problem statement tells us that exercise time is made up of time stretching and time jogging. We are given information about time stretching and asked for time jogging. The jogging time will be the difference of total exercise time and time stretching.

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Sal

Stretches 25 minutes and exercises 240 minutes during the week. His jogging time is ...

jogging time = exercise time - stretching time

jogging time = 240 min -25 min = 215 minutes . . . per week

Sal's jogging time per day was ...

(215 min/week)/(5 day/week) = 43 min/day

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Elena

Stretches 15 minutes per day for 5 days per week, and exercises 300 minutes during the week. Her jogging time is ...

jogging time = exercise time - (daily stretching time)×(days per week)

jogging time = 300 min - (15 min/day)×(5 days)

jogging time = 225 min . . . per week

Elena's jogging time per day was ...

(225 min/week)/(5 day/week) = 45 min/day

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Additional comment

We wanted to show the parallelism in the problem, so that is why we worked it the way we did. We could have found Elena's jogging time by finding her exercise time per day (300/5 = 60 min), then subtracting her stretching time per day (60 min -15 min = 45 min).

It can be useful to keep units with the numbers and to remember that numbers can only be added or subtracted if they have like units.