Question

Dara ran on a treadmill that had a readout indicating the time remaining in her exercise session. When the readout indicated 24 min 18 sec, she had completed 10% of her exercise session. The readout indicated which of the following when she had completed 40% of her exercise session?A. 10 min 48 sec

B. 14 min 52 sec
C. 14 min 58 sec
D. 16 min 6 sec
E. 16 min 12 sec

Answer 1

E. 16 min 12 sec

Explanation:

Let x represent total time taken to complete the exercise.

We have been given that Dara ran on a treadmill that had a readout indicating the time remaining in her exercise session.

When the readout indicated 24 min 18 sec, she had completed 10% of her exercise session. This means that 90% time of exercise is equal to 24 minutes and 18 seconds.

18 seconds will be equal to 0.3 minutes.

Let us find total time of exercise as:

`(90)/(100)x=24.3`

`0.90x=24.3`

`(0.90x)/(0.90)=(24.3)/(0.90)`

`x=27`

To find readout when Dara had completed 40% of her exercise session, we need to find 60% of total time.

`(60)/(100)(27)=0.60(27)=16.2`

Since our time in in minutes, so we will convert 0.2 minutes to seconds by multiplying by 60.

`0.20(60)=12`

Therefore, the readout will indicate 16 minutes 12 seconds, when Dara had completed 40% of her exercise session.