CoffeeCreamSugar wrote:
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
We are given that Dara completed 10% of her exercise session when the readout indicated 24 min and 18 seconds as her time remaining. In other words she had
90% left of her workout at that time. We need to determine the readout after she has completed 40% of her exercise, or when she has
60% left.
We can create a proportion to determine the time when Dara has 60% left. First, let’s convert 24 min 18 sec to minutes.
24 min 18 sec = (24 + 18/60) min = (24 + 3/10) min = 24.3 min
We can also express 90 percent as 90/100 = 0.9 and 60 percent as 60/100 = 0.6. We define x as the number of minutes remaining in her workout when she has 60%, or 0.6, of her workout left to do.
Our proportion is as follows:
0.9/24.3 = 0.6/x
9/243 = 0.6/x
9x = 145.8
x = 145.8/9 = 16.2 min
Thus, x = (16 + 2/10) min = (16 + 12/60) min = 16 min 12 sec
Answer: E
Why are people keep saying she completed 90% of the her workout? Please look at this solution. She completed 10% and still has 90% left!